CHE101_01_Summer21 PDF - General Chemistry

General Chemistry (CHE 101) Topics Breakdown Part I  Chemistry: The Study of Change (Chapter 1)  Atoms, Molecules and Ions (Chapter 2)  Quantum Theory and the Electronic Structure of Atoms (Chapter 7) &  Periodic Relationships Among the Elements (Chapter 8) Topics Breakdown Part I  Chemistry: The Study of Change (Q -1)  Atoms, Molecules and Ions (Q -1)  Quantum Theory and the Electronic Structure of Atoms (Q -2) &  Periodic Relationships Among the Elements (Q -2) Chapter 1 Chemistry : The study of change Chemistry...? …is a subdivision of physical science that focuses on what happens when the electron cloud of one substance encounters the electron cloud of another An atom A Sodium atom - Na Na Another atom A Chlorine atom - Cl Cl When they collide…i.e., when two atoms collide… Na Cl When two atoms collide… Electrons may be transferred (ionization occurs!) Cl- Na+ e- When two atoms collide… Electrons may be transferred (ionization occurs!) Cl- Na+ e- An ionic Bond When two H-atoms collide… H H When two H-atoms collide… Electrons may be shared H e- H e- When two H-atoms collide… Electrons may be shared A covalent bond H H Build your Molecules https://phet.colorado.edu/sims/html/build-a-molecule/latest/build-a- molecule_en.html When two H2-molecules collide… Electrons may repel each other H2 2e- 2e- H2 When two H2-molecules collide… Electrons may repel each other H2 2e- 2e- H2 When two H2-molecules collide… Electrons may repel each other H2 2e- 2e- H2 When atoms/molecules collide… We’ll study how to predict which of the Three Possibilities happens Chemistry is the central science Chemistry Chemistry is the central science Sub-atomic physics Chemistry 10 -10 m Chemistry is the central science Sub-atomic Traditional physics Chemistry physics 10 -10 m 10 -9 m When two atoms/molecules collide… Length of the covalent bond is in the specified range A covalent bond ~ 10-10 m The Scientific Method  Science is dynamic -- it’s just our “current understanding”  Involves observation and measurements  Science attempts to identify variables that control a situation  The lack of scientific understanding leaves you vulnerable to being duped. The Scientific Method Observations Hypothesis Experiments Two aspects of chemical reactions...  Kinetics - how fast the reaction occurs &  Thermodynamics - the direction in which the reaction proceeds and the degree of completeness when the action stops Matter  Has mass (measured as weight)  Occupies space (measured as volume) Energy  Rest of the “normal stuff” in the universe is energy, e.g., light  Matter and energy are related E = mc2 Modern astrophysics suggests…  Matter and energy are about 5% of the universe  Dark matter is another 25%  Dark Energy is the remaining 70%  Or we don’t quite understand how physics works at a universal scale! Changes in Chemistry Chemical changes  Chemical bonds are broken  Atoms rearrange themselves  New chemical bonds form Chemical changes  Chemical bonds are broken  Atoms rearrange themselves  New chemical bonds form C3H8 + 5 O2 Propane Molecular gas oxygen Chemical changes  Chemical bonds are broken  Atoms rearrange themselves  New chemical bonds form C3H8 + 5 O2 3 CO2 + 4 H2O Propane Molecular Carbon Water gas oxygen dioxide vapor Physical changes  Associated with changes in state (gas, liquid, solid, solution)  No chemical changes occur Water freezes to ice Ice melts to water (It’s H2O before and after) Sugar dissolves in water Water evaporates leaving sugar (It’s C12H22O11 before and after) A burning Candle is… 1. A chemical change 2. A physical change 3. Both A burning Candle is… 1. A chemical change 2. A physical change 3. Both Most real-world processes involve both kinds  When a candle burns…  Heat from the flame melts (physical change) and pyrolyzes (chemical change) wax components into gaseous vapors  Vapors burn with oxygen to form carbon dioxide and water (chemical change) Phases of Fire Phases of Fire Paraffin wax Phases of Fire Phases of Fire Phases of Fire Fuel vapor cloud forms from melting of solid wax and pyrolysis of paraffin wax (e.g., C18) to shorter fragments (e.g., C2 - C 5 ) Phases of Fire Heat from the flame provides energy to start breaking bonds in fuel and O2 so that energy- releasing rearrangements can occur Phases of Fire A flame forms around the wick as a ball of hot fuel gases that come in contact with the air at the edges Phases of Fire Let’s zoom in for a closer look here A flame forms around the wick as a ball of hot fuel gases that come in contact with the air at the edges Phases of Fire A reaction zone forms where fuel vapors and O2 come into contact. Phases of Fire Ethene, a gaseous C2 fragment H H C=C O=O H H A reaction zone forms where fuel vapors and O2 come into contact. Phases of Fire O=C=O + H-O-H H H C=C O=O H H CO2 and H2O are produced as products. They dissipate in the turbulent mixing above the flame Flaming combustion occurs in the gas phase Phases of Fire The interior of the fuel vapor ball contains soot particles (little balls of solid carbon) that are heated to various temperatures -- yellow hotter than orange hotter than red Phases of Fire 1400oC 800oC The interior of the fuel vapor ball contains soot particles (little balls of solid carbon) that are heated to various temperatures -- yellow hotter than orange hotter than red Phases of Fire When local turbulence disturbs the reaction zone envelope, some unburned soot particles escape as cool black smoke particulates that are less than 1 micron (micrometer) in diameter Black soot is most prevalent in turbulent flaming combustion zones Numbers in Chemistry The numbers associated with atoms often get too big or too small to be convenient to write in decimal notation Exponential Notation  We’ll use exponential notation to make it simpler  Scientific notation is best for our purposes – it places a decimal after the first non-zero digit The number of copper atoms in a pre-1982 penny... The number of copper atoms in a pre-1982 penny... 029 500 000 000 000 000 000 000 atoms The number of copper atoms in a pre-1982 penny... 029 500 000 000 000 000 000 000 atoms Place a decimal after the first non-zero digit (to make it scientific notation). The number of copper atoms in a pre-1982 penny... 029 500 000 000 000 000 000 000 atoms 2.95 Place a decimal after the first non-zero digit (to make it scientific notation). The number of copper atoms in a pre-1982 penny... 029 500 000 000 000 000 000 000 atoms 2.95 Place a decimal after the first non-zero digit (to make it scientific notation). The number of copper atoms in a pre-1982 penny... 029 500 000 000 000 000 000 000 atoms 21 18 15 12 9 6 3 2.95 Now count how many places the decimal has been moved. The number of copper atoms in a pre-1982 penny... 029 500 000 000 000 000 000 000 atoms 21 18 15 12 9 6 3 2.95 x 10 ? atoms Now count how many places the decimal has been moved. The number of copper atoms in a pre-1982 penny... 029 500 000 000 000 000 000 000 atoms 21 18 15 12 9 6 3 2.95 x 10 22 atoms Now count how many places the decimal has been moved. The number of copper atoms in a pre-1982 penny... 029 500 000 000 000 000 000 000 atoms 21 18 15 12 9 6 3 2.95 x 10 22 atoms The number of copper atoms in a pre-1982 penny... 029 500 000 000 000 000 000 000 atoms 21 18 15 12 9 6 3 2.95 x 10 22 atoms POSITIVE exponents tell us how many places to the LEFT we’ve moved. The number of copper atoms in a pre-1982 penny... 029 500 000 000 000 000 000 000 atoms 21 18 15 12 9 6 3 2.95 x 10 22 atoms Numbers with POSITIVE exponents are BIG The weight of a single copper atom... The weight of a single copper atom... 0.000 000 000 000 000 000 000 000 23 lbs The weight of a single copper atom... 0.000 000 000 000 000 000 000 000 23 lbs Place a decimal after the first non-zero digit. The weight of a single copper atom... 0.000 000 000 000 000 000 000 000 23 lbs 2.3 Place a decimal after the first non-zero digit. The weight of a single copper atom... 0.000 000 000 000 000 000 000 000 23 lbs 2.3 Place a decimal after the first non-zero digit. The weight of a single copper atom... 0.000 000 000 000 000 000 000 000 23 lbs 2.3 Now count how many places the decimal has been moved. The weight of a single copper atom... 0.000 000 000 000 000 000 000 000 23 lbs 3 6 9 12 15 18 21 24 2.3 Now count how many places the decimal has been moved. The weight of a single copper atom... 0.000 000 000 000 000 000 000 000 23 lbs 3 6 9 12 15 18 21 24 2.3 x 10? lbs Now count how many places the decimal has been moved. The weight of a single copper atom... 0.000 000 000 000 000 000 000 000 23 lbs 3 6 9 12 15 18 21 24 2.3 x 10-25 lbs Now count how many places the decimal has been moved. The weight of a single copper atom... 0.000 000 000 000 000 000 000 000 23 lbs 3 6 9 12 15 18 21 24 2.3 x 10-25 lbs NEGATIVE exponents tell us how many places to the RIGHT we’ve moved. The weight of a single copper atom... 0.000 000 000 000 000 000 000 000 23 lbs 3 6 9 12 15 18 21 24 2.3 x 10-25 lbs Numbers with NEGATIVE exponents are SMALL The correct scientific notation for 0.000 000 000 000 041 is… 1. 41 x 10-15 2. 4.1 x 1014 3. 4.1 x 10-14 4. 4.1 x 10-15 The correct scientific notation for 0.000 000 000 000 041 is… 3 6 9 12 1. 41 x 10-15 2. 4.1 x 1014 3. 4.1 x 10-14 4. 4.1 x 10-15 The correct scientific notation for 0.000 000 000 000 041 is… 3 6 9 12 1. 41 x 10-15 14 places to the right 2. 4.1 x 1014 3. 4.1 x 10-14 scientific notation 4. 4.1 x 10-15 The correct scientific notation for 0.000 000 000 000 041 is… 3 6 9 12 15 places to the right 1. 41 x 10-15 2. 4.1 x 1014 engineering notation 3. 4.1 x 10-14 (the exponent is evenly divisible by 4. 4.1 x 10-15 three) Calculations with scientific notation  Rules are given in any standard textbook  Different rules apply for multiplication/division vs. addition/subtraction  Most common error is entering scientific notation on your calculator  Need to learn the “exp” or “EE” key or the “x10x” key We’ll do calculations like... We’ll do calculations like... (3.5 x 10 3 ) 2 4.1 x 10 -4 We’ll do calculations like... (3.5 x 10 3 )(3.5 x 10 3 ) 1.225 x 10 7 = 4.1 x 10 -4 4.1 x 10 -4 = 2.987804878 x 10 10 , 2019 Discovered on federal land in Montana Tyrannosaurus rex dominated the tail end of the dinosaur age. Significant Figures  The USPS issued a dinosaur stamp sheet in 1996 also  The stamp sheet reads “A scene in Colorado 150,000,000 years ago” A scene in Colorado 150 million years ago ©USPS 1996 The World of Dinosaur stamps was issued on May 1, 1997 in Grand Junction, Colorado, USA. This set of fifteen U.S stamps feature prehistoric dinosaurs from North America during Jurassic and Cretaceous periods. Significant Figures  The USPS issued a dinosaur stamp sheet in 1996  The stamp sheet reads “A scene in Colorado 150,000,000 years ago”  Since it’s now 2021, shouldn’t we say “A scene in Colorado 150,000,025 years ago”? Significant Figures  The USPS issued a dinosaur stamp sheet in 1996  The stamp sheet reads “A scene in Colorado 150,000,000 years ago”  Since it’s now 2021, shouldn’t we say “A scene in Colorado 150,000,021 years ago”?  Significant figures do not include uncertain digits or place-holding zeroes. Significant Figures  The USPS issued a dinosaur stamp sheet in 1996  The stamp sheet reads “A scene in Colorado 150,000,000 years ago”  Since it’s now 2021, shouldn’t we say “A scene in Colorado 150,000,025 years ago”?  Significant figures do not include uncertain digits or place-holding zeroes. Significant Figures  The USPS issued a dinosaur stamp sheet in 1996  The stamp sheet reads “A scene in Colorado 150,000,000 years ago”  Since it’s now 2021, shouldn’t we say, “A scene in Colorado 150,000,025 years ago”?  Significant figures do not include uncertain digits or place-holding zeroes. Significant Figures  The USPS issued a dinosaur stamp sheet in 1996  The stamp sheet reads “A scene in Colorado 150,000,000 years ago”  Since it’s now 2021, shouldn’t we say “A scene in Colorado 150,000,025 years ago”  Significant figures do not include uncertain digits or place-holding zeroes. Only 2 significant figures We’ll do calculations like... (3.5 x 10 3 )(3.5 x 10 3 ) 1.225 x 10 7 = 4.1 x 10 -4 4.1 x 10 -4 Values used only = 2.987804878 x 10 10 have two significant figures We’ll do calculations like... (3.5 x 10 3 )(3.5 x 10 3 ) 1.225 x 10 7 = 4.1 x 10 -4 4.1 x 10 -4 Values used only = 2.987804878 x 10 10 have two significant figures We’ll do calculations like... (3.5 x 10 3 )(3.5 x 10 3 ) 1.225 x 10 7 = 4.1 x 10 -4 4.1 x 10 -4 Values used only = 2.987804878 x 10 10 have two significant Uncertain digits figures We’ll do calculations like... (3.5 x 10 3 )(3.5 x 10 3 ) 1.225 x 10 7 = 4.1 x 10 -4 4.1 x 10 -4 = 2.987804878 x 10 10 Two significant figures in our = 3.0 x 10 10 answer We’ll do calculations like... (3.5 x 10 3 )(3.5 x 10 3 ) 1.225 x 10 7 = 4.1 x 10 -4 4.1 x 10 -4 = 2.987804878 x 10 10 This requires rounding = 3.0 x 10 10 We’ll do calculations like... (3.5 x 10 3 )(3.5 x 10 3 ) 1.225 x 10 7 = 4.1 x 10 -4 4.1 x 10 -4 = 2.987804878 x 10 10 = 3.0 x 10 10 Significant Figure Practice  Determining significant figures is a snap  No decimal present? Toss out any trailing zeroes  Decimal present? Toss out any leading zeroes How many sig figs in 0.0003007? 1. 2 2. 4 3. 7 4. 8 How many sig figs in 0.0003007? 1. 2 2. 4 3. 7 4. 8 Significant Figure Practice  0.0003007 (4 sig figs) Significant Figure Practice  0.0003007 (4 sig figs) A decimal is present, so we drop the leading zeroes How many sig figs in 15.00? 1. 2 2. 3 3. 4 How many sig figs in 15.00? 1. 2 2. 3 3. 4 Significant Figure Practice  0.0003007 (4 sig figs)  15.00 (4 sig figs, we wouldn’t have ……………….written those last two zero’s A decimal is ……………….if they weren’t measurable) present but there are no leading zeroes to drop! How many sig figs in 1200? 1. 2 2. 3 3. 4 How many sig figs in 1200? 1. 2 2. 3 3. 4 Significant Figure Practice  0.0003007 (4 sig figs)  15.00 (4 sig figs, we wouldn’t have ……………….written those last two zero’s ……………….if they weren’t measurable)  1200 (2 sig figs) Significant Figure Practice  0.0003007 (4 sig figs)  15.00 (4 sig figs, we wouldn’t have ……………….written those last two zero’s ……………….if they weren’t measurable)  1200 (2 sig figs) No decimal present so we drop trailing zeroes Significant Figure Practice  0.0003007 (4 sig figs)  15.00 (4 sig figs, we wouldn’t have ……………….written those last two zero’s ……………….if they weren’t measurable)  1200 (2 sig figs) What if there were actually 3 or 4 sig figs? Significant Figure Practice  0.0003007 (4 sig figs)  15.00 (4 sig figs, we wouldn’t have ……………….written those last two zero’s ……………….if they weren’t measurable)  1200 (2 sig figs) What if there were actually 3 or 4 sig figs? 1.2 x 103 (2 sig figs) 1.20 x 103 (3 sig figs) ……1.200 x 103 (4 sig figs) Significant Figure Practice  0.0003007 (4 sig figs)  15.00 (4 sig figs, we wouldn’t have ……………….written those last two zero’s ……………….if they weren’t measurable)  1200 (2 sig figs) All figs are sig in scientific notation!!!!!! 1.2 x 103 (2 sig figs) 1.20 x 103 (3 sig figs) ……1.200 x 103 (4 sig figs) Significant Figure Practice  0.0003007 (4 sig figs)  15.00 (4 sig figs, we wouldn’t have ……………….written those last two zero’s ……………….if they weren’t measurable)  1200 (2 sig figs) Decimal present but no leading zeroes 1.2 x 103 (2 sig figs) 1.20 x 103 (3 sig figs) ……1.200 x 103 (4 sig figs) Try this one now (8.30 x 10 -4)(5.5 x 10 -6) 6.9 x 10 3 = ? 1. 6.6 x 10-7 2. 6.6159 x 10-13 3. 2.2 x 10-2 4. 6.6 x 10-13 Try this one now (8.30 x 10 -4)(5.5 x 10 -6) 6.9 x 10 3 = ? 1. 6.6 x 10-7 2. 6.6159 x 10-13 3. 2.2 x 10-2 4. 6.6 x 10-13 Try this one now... (8.30 x 10 -4)(5.5 x 10 -6) 6.9 x 10 3 = Try this one now... (8.30 x 10 -4)(5.5 x 10 -6) 6.9 x 10 3 = 6.615942028986 x 10 -13 Here’s the button sequence I would use: 8. 3 0 2nd EE (-) 4 x 5. 5 2nd EE (-) 6  6. 9 2nd EE 3 Try this one now... 3 sig. figs. (8.30 x 10 -4)(5.5 x 10 -6) 6.9 x 10 3 = 2 sig. figs. 6.615942028986 x 10 -13 Our answer should have no more sig figs than any of our starting values Try this one now... (8.30 x 10 -4)(5.5 x 10 -6) 6.9 x 10 3 = 2 sig. figs. 6.615942028986 x 10 -13 = 6.6 x 10 -13 Our answer should have no more sig figs than any of our starting values A subtle calculator error (8.30 x 10 -4)(5.5 x 10 -6) 6.9 x 10 3 = 6.615942028986 x 10 -13 = 6.6 x 10 -13 Try this one now... (8.30 x 10 -4)(5.5 x 10 -6) 6.9 x 10 3 = What is 2.3 x 10-3 written as a non-exponential number? 1. 0.0023 2. 2300 3. 23000 4. 0.023 What is 2.3 x 10-3 written as a non-exponential number? 1. 0.0023 The negative exponent 2. 2300 means we’re dealing with 3. 23000 a number less than 1. 4. 0.023 What is 2.3 x 10-3 written as a non-exponential number? 1. 0.0023 The negative exponent 2. 2300 means we’re dealing with 3. 23000 a number less than 1. 4. 0.023 What is 2.3 x 10-3 written as a non-exponential number? 1. 0.0023 -3 means we’ve moved the 2. 2300 decimal point three places 3. 23000 to the right from where it 4. 0.023 originally was What is 2.3 x 10-3 written as a non-exponential number? 1. 0.0023 -3 means we’ve moved the 2. 2300 decimal point three places 3. 23000 to the right from where it 4. 0.023 originally was 0002.3 3 places What is 2.3 x 10-3 written as a non-exponential number? 1. 0.0023 -3 means we’ve moved the 2. 2300 decimal point three places 3. 23000 to the right from where it 4. 0.023 originally was 0.0023 3 places What is 2.3 x 10-3 written as a non-exponential number? 1. 0.0023 -3 means we’ve moved the 2. 2300 decimal point three places 3. 23000 to the right from where it 4. 0.023 originally was 0.0023 Express 56 100 000 000 in scientific notation 1. 5.61 x 109 2. 5.61 x 10-10 3. 5.61 x 1010 4. 5.61 x 1011 Express 56 100 000 000 in scientific notation 1. 5.61 x 109 2. 5.61 x 10-10 3. 5.61 x 1010 4. 5.61 x 1011 Our answer will have a positive exponent since the number is bigger than 1 Express 56 100 000 000 in scientific notation 1. 5.61 x 109 We need to move 2. 5.61 x 10-10 the decimal 10 3. 5.61 x 1010 places to position it between the first 4. 5.61 x 1011 two non-zero digits 56 100 000 000 9 6 3 Express 56 100 000 000 in scientific notation 1. 5.61 x 109 We need to move 2. 5.61 x 10-10 the decimal 10 3. 5.61 x 1010 places to position it between the first 4. 5.61 x 1011 two non-zero digits 56 100 000 000 9 6 3 How many sig figs?  0.00003500 How many sig figs?  0.00003500 4 decimal present ….toss leading zeros How many sig figs?  0.00003500 4 decimal present ….toss leading zeros  6,700,300 000 How many sig figs?  0.00003500 4 decimal present ….toss leading zeros  6,700,300 000 5 no decimal present ….toss trailing zeros How many sig figs?  0.00003500 4 decimal present ….toss leading zeros  6,700,300 000 5 no decimal present ….toss trailing zeros  327.000 How many sig figs?  0.00003500 4 decimal present ….toss leading zeros  6,700,300 000 5 no decimal present ….toss trailing zeros  327.000 6 decimal present no leading zeros Calculate with sig figs… 4.2 x 10 3 (2 x 10 -6)(7.1 x 10 -3) = ? 1. 3 x 1011 2. 1.5 x 107 3. 1 x 107 4. 3.0 x 1011 Calculate with sig figs… 4.2 x 10 3 (2 x 10 -6)(7.1 x 10 -3) = ? 1. 3 x 1011 2. 1.5 x 107 3. 1 x 107 4. 3.0 x 1011 Calculate with sig figs… 2 s.f. 4.2 x 10 3 (2 x 10 -6)(7.1 x 10 -3) = ? 1 s.f. 2 s.f. The calculator sees it as: (4.2E3)  (2E–6)  (7.1E– 3) = 2.957746479 x 1011 How many sig figs? Calculate with sig figs… 2 s.f. 4.2 x 10 3 (2 x 10 -6)(7.1 x 10 -3) = ? 1 s.f. 2 s.f. The calculator sees it as: (4.2E3)  (2E–6)  (7.1E– 3) = 2.957746479 x 1011 How many sig figs? We only get 1 s.f.! Calculate with sig figs… 2 s.f. 4.2 x 10 3 -6)(7.1 -3) = 3 x 1011 (2 x 10 x 10 1 s.f. 2 s.f. The calculator sees it as: (4.2E3)  (2E–6)  (7.1E– 3) = 2.957746479 x 1011 How many sig figs? We only get 1 s.f.! Measurements  Measurements consist of two parts… A number The associated units Consider a distance of 872  872 miles  872 light years  872 nanometers  872 smoots Unit Systems  Metric  Systeme International d’Unites (SI)  English Unit Systems  Metric  Systeme International d’Unites (SI)  English Only still in use in US, Liberia and Burma Although many metric units used in US, e.g., mg in doses of medicine and L for large soda bottles Basic metric system  Length in meters (m)  Volume in cubic meters (m3) or liters (L) or cm3 (cc’s)  Mass in grams (g)  Time in seconds (s) Unit prefixes Unit prefixes Units often turn out to be inconveniently large or small. Unit prefixes Units often turn out to be inconveniently large or small. Green light is 0. 000 000 550 m (5.50 x 10-7 m) Unit prefixes Units often turn out to be inconveniently large or small. Green light is 0. 000 000 550 m milli (5.50 x 10-7 m) Unit prefixes Units often turn out to be inconveniently large or small. Green light is 0. 000 000 550 m milli micro (5.50 x 10-7 m) Unit prefixes Units often turn out to be inconveniently large or small. Green light is 0. 000 000 550 m milli micro nano (5.50 x 10-7 m) Unit prefixes Units often turn out to be inconveniently large or small. Green light is 0. 000 000 550 m milli micro nano (5.50 x 10-7 m) Nicer to say 550 nanometers (nm) Unit prefixes Units often turn out to be inconveniently large or small. Green light is 0. 000 000 550 m milli micro nano (5.50 x 10-7 m) thousandths Nicer to say millionths 550 nanometers (nm) billionths Unit prefixes Units often turn out to be inconveniently large or small. Green light is 0. 000 000 550 m milli micro nano (5.50 x 10-7 m) thousandths Nicer to say millionths 550 nanometers (nm) billionths 550 billionths of a meter Unit prefixes to learn... giga- (G) 109 1 Gg = 109 g billions mega- (M) 106 1 Mg = 106 g millions kilo- (k) 103 1 kg = 103 g thousands deci- (d) 10-1 1 dg = 10-1 g tenths centi- (c) 10-2 1 cg = 10-2 g hundredths milli- (m) 10-3 1 mg = 10-3 g thousandths micro- (m) 10-6 1 mg = 10-6 g millionths nano- (n) 10-9 1 ng = 10-9 g billionths pico- (p) 10-12 1 pg = 10-12g trillionths Unit prefixes to learn... giga- (G) 109 1 Gg = 109 g billions mega- (M) 106 1 Mg = 106 g millions kilo- (k) 103 1 kg = 103 g thousands deci- (d) 10-1 1 dg = 10-1 g tenths centi- (c) 10-2 1 cg = 10-2 g hundredths milli- (m) 10-3 1 mg = 10-3 g thousandths micro- (m) 10-6 1 mg = 10-6 g millionths nano- (n) 10-9 1 ng = 10-9 g billionths pico- (p) 10-12 1 pg = 10-12g trillionths I’ve placed a 1 in front of each prefixed unit in this table Unit prefixes to learn... giga- (G) 109 Gee! billions mega- (M) 106 Megan millions kilo- (k) 103 killed thousands deci- (d) 10-1 Desi’s tenths centi- (c) 10-2 scent. hundredths milli- (m) 10-3 Millie thousandths micro- (m) 10-6 microwaved millionths nano- (n) 10-9 Nan’s billionths pico- (p) 10-12 Piccolo. trillionths Here’s two nonsense phrases to help you remember these prefixes in order Unit prefixes to learn... giga- (G) 109 1 Gg = 109 g billions mega- (M) 106 1 Mg = 106 g millions kilo- (k) 103 1 kg = 103 g thousands deci- (d) 10-1 1 dg = 10-1 g tenths centi- (c) 10-2 1 cg = 10-2 g hundredths milli- (m) 10-3 1 mg = 10-3 g thousandths micro- (m) 10-6 1 mg = 10-6 g millionths nano- (n) 10-9 1 ng = 10-9 g billionths pico- (p) 10-12 1 pg = 10-12g trillionths How many microliters (mL) are there in 3.27 x 10-5 L? 1. 0.0327 mL 2. 3.27 mL 3. 32.7 mL 4. 327 mL Unit prefixes to learn... giga- (G) 109 1 Gg = 109 g billions mega- (M) 106 1 Mg = 106 g millions kilo- (k) 103 1 kg = 103 g thousands deci- (d) 10-1 1 dg = 10-1 g tenths centi- (c) 10-2 1 cg = 10-2 g hundredths milli- (m) 10-3 1 mg = 10-3 g thousandths micro- (m) 10-6 1 mg = 10-6 g millionths nano- (n) 10-9 1 ng = 10-9 g billionths pico- (p) 10-12 1 pg = 10-12g trillionths Find the best prefix by looking for an exponent equal to or smaller than your value. We have 3.27 x 10-5, so Unit prefixes to learn... giga- (G) 109 1 Gg = 109 g billions mega- (M) 106 1 Mg = 106 g millions kilo- (k) 103 1 kg = 103 g thousands deci- (d) 10-1 1 dg = 10-1 g tenths centi- (c) 10-2 1 cg = 10-2 g hundredths milli- (m) 10-3 1 mg = 10-3 g thousandths micro- (m) 10-6 1 mg = 10-6 g millionths nano- (n) 10-9 1 ng = 10-9 g billionths pico- (p) 10-12 1 pg = 10-12g trillionths Find the best prefix by looking for an exponent equal to or smaller than your value. We have 3.27 x 10-5, so Unit prefixes to learn... giga- (G) 109 1 Gg = 109 g billions mega- (M) 106 1 Mg = 106 g millions kilo- (k) 103 1 kg = 103 g thousands deci- (d) 10-1 1 dg = 10-1 g tenths centi- (c) 10-2 1 cg = 10-2 g hundredths milli- (m) 10-3 1 mg = 10-3 g thousandths micro- (m) 10-6 1 mg = 10-6 g millionths nano- (n) 10-9 1 ng = 10-9 g billionths pico- (p) 10-12 1 pg = 10-12g trillionths Values that have an exponent of 10-6 or 10-5 or 10-4 can be nicely expressed using the prefix micro Unit prefixes to learn... giga- (G) 109 1 Gg = 109 g billions mega- (M) 106 1 Mg = 106 g millions kilo- (k) 103 1 kg = 103 g thousands deci- (d) 10-1 1 dg = 10-1 g tenths centi- (c) 10-2 1 cg = 10-2 g hundredths milli- (m) 10-3 1 mg = 10-3 g thousandths micro- (m) 10-6 1 mg = 10-6 g millionths nano- (n) 10-9 1 ng = 10-9 g billionths pico- (p) 10-12 1 pg = 10-12g trillionths 10-6 = 1 – 9 10-5 = 10 – 99 3.27 x 10-5 10-4 = 100 – 999 How many microliters (mL) are there in 3.27 x 10-5 L? 1. 0.0327 mL 2. 3.27 mL 3. 32.7 mL 4. 327 mL How many microliters (mL) are there in 3.27 x 10-5 L? 1. 0.0327 mL 2. 3.27 mL 3. 32.7 mL 4. 327 mL How many microliters (mL) are there in 3.27 x 10-5 L? How many microliters (mL) are there in 3.27 x 10-5 L?  Written in non-exponential form this is 0. 000 032 7 L How many microliters (mL) are there in 3.27 x 10-5 L?  Written in non-exponential form this is 0. 000 032 7 L milli How many microliters (mL) are there in 3.27 x 10-5 L?  Written in non-exponential form this is 0. 000 032 7 L milli micro How many microliters (mL) are there in 3.27 x 10-5 L?  Written in non-exponential form this is 0. 000 032 7 L milli micro Answer: 32.7 mL Unit prefixes to learn... giga- (G) 109 1 Gg = 109 g billions mega- (M) 106 1 Mg = 106 g millions kilo- (k) 103 1 kg = 103 g thousands deci- (d) 10-1 1 dg = 10-1 g tenths centi- (c) 10-2 1 cg = 10-2 g hundredths milli- (m) 10-3 1 mg = 10-3 g thousandths micro- (m) 10-6 1 mg = 10-6 g millionths nano- (n) 10-9 1 ng = 10-9 g billionths pico- (p) 10-12 1 pg = 10-12g trillionths How many microliters (mL) are there in 3.27 x 10-5 L?  Written in non-exponential form this is 0. 000 032 7 L milli micro 32.7 millionths Answer: 32.7 mL How many grams are in 350 milligrams (mg)? 1. 0.350 g 2. 3.50 g 3. 3.50 x 10-1 g 4. 350 x 10-3 g How many grams are in 350 milligrams (mg)? 1. 0.350 g Just replace the “m” 2. 3.50 g for “milli-” with the 3. 3.50 x 10-1 g exponent from the 4. 350 x 10-3 g prefix table 350 mg How many grams are in 350 milligrams (mg)? 1. 0.350 g Just replace the “m” 2. 3.50 g for “milli-” with the 3. 3.50 x 10-1 g exponent from the 4. 350 x 10-3 g prefix table 350 mg milli- means 10-3 How many grams are in 350 milligrams (mg)? 1. 0.350 g Just replace the “m” 2. 3.50 g for “milli-” with the 3. 3.50 x 10-1 g exponent from the 4. 350 x 10-3 g prefix table 350 x 10-3 g milli- means 10-3 How many grams are in 350 milligrams (mg)? 1. 0.350 g Now enter this 2. 3.50 g number in your 3. 3.50 x 10-1 g calculator using the 4. 350 x 10-3 g proper keystrokes… 3 5 0 “EE” (-) 3 350 x 10-3 g milli- means 10-3 How many grams are in 350 milligrams (mg)? 1. 0.350 g Now enter this 2. 3.50 g number in your 3. 3.50 x 10-1 g calculator using the 4. 350 x 10-3 g proper keystrokes… 3 5 0 “EE” (-) 3 3.50 x 10-1 g milli- means 10-3 How many grams are in 350 milligrams (mg)? 1. 0.350 g Now enter this 2. 3.50 g number in your 3. 3.50 x 10-1 g calculator using the 4. 350 x 10-3 g proper keystrokes… 3 5 0 “EE” (-) 3 3.50 x 10-1 g milli- means 10-3 How many grams are in 350 milligrams (mg)? This is an equivalent 1. 0.350 g answer! 2. 3.50 g 3. 3.50 x 10-1 g 4. 350 x 10-3 g 3.50 x 10-1 g milli- means 10-3 How many grams are in 350 milligrams (mg)? This is an equivalent 1. 0.350 g answer! 2. 3.50 g 3. 3.50 x 10-1 g 4. 350 x 10-3 g As is this! 3.50 x 10-1 g milli- means 10-3 How many grams are in 350 milligrams (mg)? 1. 0.350 g Floating- or fixed-point 2. 3.50 g decimal notation 3. 3.50 x 10-1 g Scientific notation 4. 350 x 10-3 g Engineering notation 3.50 x 10-1 g milli- means 10-3 Temperature Systems  Metric: Celsius (or centigrade)  SI: Kelvin  English: Fahrenheit Celsius vs. Kelvin  Both scales have the same size of degree  100 steps between freezing point and boiling point of water Celsius goes from 0 to 100 Kelvin goes from 273 to 373 Fahrenheit Scale  Has 180 steps between freezing and boiling points of water 1o Celsius = 1.8o Fahrenheit  The scales also differ in their starting points 32 oF = 0 oC Temperature Scales Fahrenheit Celsius Kelvin Freezing Point of Water Water 32 0 273 freezes Fahrenheit Celsius Kelvin Boiling Point of Water 212 100 373 Water boils Water 32 0 273 freezes Fahrenheit Celsius Kelvin Absolute Zero 212 100 373 Water boils Water 32 0 273 freezes Absolute -459 -273 0 zero Fahrenheit Celsius Kelvin Body Temperature 212 100 373 Water boils 98.6 37 310 Water 32 0 273 freezes Absolute -459 -273 0 zero Fahrenheit Celsius Kelvin Crossover Point 212 100 373 Water boils 98.6 37 310 Water 32 0 273 freezes -40 -40 233 Absolute -459 -273 0 zero Fahrenheit Celsius Kelvin Crossover Point 212 100 373 Water boils 98.6 37 310 Water 32 0 273 freezes -40 -40 233 Fahrenheit and Celsius thermometers read the same at -40o! Absolute -459 -273 0 zero Fahrenheit Celsius Kelvin Celsius/Kelvin Conversions K = oC + 273 oC = K - 273 If the temperature outside is 263 K, what season is it? (Calculate the equivalent oC) 1. Summer 2. Fall 3. Winter 4. Spring If the temperature outside is 263 K, what season is it? (Calculate the equivalent oC) oC = K - 273 1. Summer 2. Fall We’ll use the “oC =“ 3. Winter form since we want our 4. Spring answer in oC. If the temperature outside is 263 K, what season is it? (Calculate the equivalent oC) oC = K - 273 1. Summer oC = 263 - 273 2. Fall 3. Winter 4. Spring If the temperature outside is 263 K, what season is it? (Calculate the equivalent oC) oC = K - 273 1. Summer oC = 263 - 273 2. Fall 3. Winter 4. Spring If the temperature outside is 263 K, what season is it? (Calculate the equivalent oC) oC = K - 273 1. Summer oC = 263 - 273 2. Fall oC = - 10 (Brr! It feels 3. Winter …………like winter!) 4. Spring If the temperature outside is 263 K, what season is it? (Calculate the equivalent oC) oC = K - 273 1. Summer oC = 263 - 273 2. Fall oC = - 10 (Brr! It feels 3. Winter …………like winter!) 4. Spring Fahrenheit Scale  Has 180 steps between freezing and boiling points of water 1o Celsius = 1.8o Fahrenheit  The scales also differ in their starting points 32 oF = 0 oC Crossover Point 212 100 373 Water boils 98.6 37 310 Water 32 0 273 freezes -40 -40 233 Absolute -459 -273 0 zero Fahrenheit Celsius Kelvin Celsius/Fahrenheit Conversions oF = (1.8 x oC) + 32 Celsius/Fahrenheit Conversions oF = (1.8 x oC) + 32 oC (oF - 32) = 1.8 Celsius/Fahrenheit Conversions oF = (1.8 x oC) + 32 oC (oF - 32) = 1.8 Here’s the adjustment Some books use 9/5 or for the difference in 5/9 instead of the 1.8 degree size (180 steps vs. 100 steps) Celsius/Fahrenheit Conversions oF = (1.8 x oC) + 32 Here’s the zero point offset oC (oF - 32) adjustment = 1.8 A Sample Calculation…..  On January 23rd, 2008 the overnight low temperature at the Missoula International airport was -3 oF. A Sample Calculation…..  On January 23rd, 2008 the overnight low temperature at the Missoula International airport was -3 oF. What is the equivalent temperature on the Celsius scale? A Sample Calculation…..  On January 23rd, 2008 the overnight low temperature at the Missoula International airport was -3 oF. What is the equivalent temperature on the Celsius scale? oC (oF - 32) = 1.8 A Sample Calculation…..  On January 23rd, 2008 the overnight low temperature at the Missoula International airport was -3 oF. What is the equivalent temperature on the Celsius scale? oC (oF - 32) = 1.8 We use this form because we want our answer in oC A Sample Calculation…..  On January 23rd, 2008 the overnight low temperature at the Missoula International airport was -3 oF. What is the equivalent temperature on the Celsius scale? oC (oF - 32) = 1.8 A Sample Calculation…..  On January 23rd, 2008 the overnight low temperature at the Missoula International airport was -3 oF. What is the equivalent temperature on the Celsius scale? oC (-3 - 32) = 1.8 A Sample Calculation…..  On January 23rd, 2008 the overnight low temperature at the Missoula International airport was -3 oF. What is the equivalent temperature on the Celsius scale? oC (-3 - 32) = Need parens 1.8 here to force subtraction before division A Sample Calculation…..  On January 23rd, 2008 the overnight low temperature at the Missoula International airport was -3 oF. What is the equivalent temperature on the Celsius scale? oC (-3 - 32) = Need parens Keystroke sequence is: 1.8 here to force ( (-) 3 - 3 2 )  1. 8 subtraction before division A Sample Calculation…..  On January 23rd, 2008 the overnight low temperature at the Missoula International airport was -3 oF. What is the equivalent temperature on the Celsius scale? oC (-3 - 32) -35 = = 1.8 1.8 A Sample Calculation…..  On January 23rd, 2008 the overnight low temperature at the Missoula International airport was -3 oF. What is the equivalent temperature on the Celsius scale? oC (-3 - 32) -35 = = 1.8 1.8 = -19.4444444 oC A Sample Calculation…..  On January 23rd, 2008 the overnight low temperature at the Missoula International airport was -3 oF. What is the equivalent temperature on the Celsius scale? In subtracting, sig fig rules say retain the fewest decimal places oC (-3 - 32) -35 = = 1.8 1.8 = -19.4444444 oC A Sample Calculation…..  On January 23rd, 2008 the overnight low temperature at the Missoula International airport was -3 oF. What is the equivalent temperature on the Celsius scale? Both the 3 and the 32 are good to 1 degree, so answer is too. oC (-3 - 32) -35 = = 1.8 1.8 = -19.4444444 oC A Sample Calculation…..  On January 23rd, 2008 the overnight low temperature at the Missoula International airport was -3 oF. What is the equivalent temperature on the Celsius scale? 2 s.f. oC (-3 - 32) -35 = = 1.8 1.8 2 s.f. = -19.4444444 oC A Sample Calculation…..  On January 23rd, 2008 the overnight low temperature at the Missoula International airport was -3 oF. What is the equivalent temperature on the Celsius scale? 2 s.f. oC (-3 - 32) -35 = = 1.8 1.8 2 s.f. = -19.4444444 oC = -19 oC 2 s.f. Check your answer... 212 100 373 Water boils 98.6 37 310 Water 32 0 273 freezes -3 -19 -40 -40 233 Absolute -459 -273 0 zero Fahrenheit Celsius Kelvin A Sample Calculation…..  On January 23rd, 2008 the overnight low temperature at the Missoula International airport was -3 oF. What is the equivalent temperature on the Celsius scale? oC (-3 - 32) -35 = = oC 1.8 1.8 You get -20.8 if you forget to = -19.4444444 oC = -19 oC include parens! If the temperature is 16oC, what is this in oF? 1. -8.9 oF 2. 86.4 oF 3. 60.8 4. 61 If the temperature is 16oC, what is this in oF? oF = (1.8 x oC) + 32 1. -8.9 oF 2. 86.4 oF 3. 60.8 4. 61 If the temperature is 16oC, what is this in oF? oF = (1.8 x oC) + 32 1. -8.9 oF oF = (1.8 x 16) + 32 2. 86.4 oF 3. 60.8 4. 61 If the temperature is 16oC, what is this in oF? oF = (1.8 x oC) + 32 1. -8.9 oF oF = (1.8 x 16) + 32 2. 86.4 oF o F = (28.8) + 32 3. 60.8 4. 61 If the temperature is 16oC, what is this in oF? oF = (1.8 x oC) + 32 1. -8.9 oF oF = (1.8 x 16) + 32 2. 86.4 oF o F = (28.8) + 32 3. 60.8 o F = 60.8 4. 61 If the temperature is 16oC, what is this in oF? oF = (1.8 x oC) + 32 1. -8.9 oF oF = (1.8 x 16) + 32 2. 86.4 oF o F = (28.8) + 32 3. 60.8 o F = 60.8 4. 61 o F = 61 (with sig figs – 28.8 should be rounded up to 29) If the temperature is 16oC, what is this in oF? oF = (1.8 x oC) + 32 1. -8.9 oF oF = (1.8 x 16) + 32 2. 86.4 oF o F = (28.8) + 32 3. 60.8 o F = 60.8 4. 61 o F = 61 Unit Conversions  Lab, clinic or field situations often require information in a form different from the way it’s supplied How many grams of a chemical are needed to make the right solution concentration? How many cc’s of medication (based on a patient’s weight) is the proper dose? How much of a toxic substance will be passed up the food-chain if an osprey eats a contaminated fish? The Factor-Label Method  Uses conversion factors to go between unit systems The Factor-Label Method  Uses conversion factors to go between unit systems Starting x quantity The Factor-Label Method  Uses conversion factors to go between unit systems Starting Conversion x quantity factor(s) The Factor-Label Method  Uses conversion factors to go between unit systems Starting Conversion Equivalent x = quantity factor(s) quantity Conversion Factors  In use, a conversion factor will appear as a fraction Conversion Factors  In use, a conversion factor will appear as a fraction 1.609 km 1.000 mile Conversion Factors  In use, a conversion factor will appear as a fraction 1.609 km 1.000 mile or 1.000 mile 1.609 km Conversion Factors  In use, a conversion factor will appear as a fraction 1.609 km 1.000 mile or 1.000 mile 1.609 km  The orientation depends on which one makes units cancel Sample calculation...  In the Olympics, how long is the marathon event in kilometers? I know it’s 26.22 miles long (26 miles 385 yds).  It commemorates the legendary feat of Pheidippides who ran from Marathon to Athens in 490 B.C.E. to announce the Greek victory over the Persians. Sample calculation...  In the Olympics, how long is the marathon event in kilometers? I know it’s 26.22 miles long (26 miles 385 yds). Starting quantity Sample calculation...  In the Olympics, how long is the marathon event in kilometers? I know it’s 26.22 miles long (26 miles 385 yds). 26.22 miles Sample calculation...  In the Olympics, how long is the marathon event in kilometers? I know it’s 26.22 miles long (26 miles 385 yds). 26.22 miles Units of answer Sample calculation...  In the Olympics, how long is the marathon event in kilometers? I know it’s 26.22 miles long (26 miles 385 yds). 26.22 miles km Sample calculation...  In the Olympics, how long is the marathon event in kilometers? I know it’s 26.22 miles long (26 miles 385 yds). 26.22 miles km Now acquire a conversion factor that relates miles and km Sample calculation...  In the Olympics, how long is the marathon event in kilometers? I know it’s 26.22 miles long (26 miles 385 yds). 26.22 miles km Arrange it so that miles are on the bottom and will cancel out Sample calculation...  In the Olympics, how long is the marathon event in kilometers? I know it’s 26.22 miles long (26 miles 385 yds). 1.609 km 26.22 miles km 1.000 mile Arrange it so that miles are on the bottom and will cancel out Sample calculation...  In the Olympics, how long is the marathon event in kilometers? I know it’s 26.22 miles long (26 miles 385 yds). 1.609 km 26.22 miles x km 1.000 mile Miles will cancel out Sample calculation...  In the Olympics, how long is the marathon event in kilometers? I know it’s 26.22 miles long (26 miles 385 yds). 1.609 km 26.22 miles x km 1.000 mile Sample calculation...  In the Olympics, how long is the marathon event in kilometers? I know it’s 26.22 miles long (26 miles 385 yds). 1.609 km 26.22 miles x km 1.000 mile Remaining units are same as answer units Sample calculation...  In the Olympics, how long is the marathon event in kilometers? I know it’s 26.22 miles long (26 miles 385 yds). 1.609 km 26.22 miles x km 1.000 mile Now do the math Sample calculation...  In the Olympics, how long is the marathon event in kilometers? I know it’s 26.22 miles long (26 miles 385 yds). 1.609 km 26.22 miles x km 1.000 mile 26.22 x 1.609 1.000 Sample calculation...  In the Olympics, how long is the marathon event in kilometers? I know it’s 26.22 miles long (26 miles 385 yds). 1.609 km 26.22 miles x km 1.000 mile 26.22 x 1.609 The 1.000 drops out 1.000 Sample calculation...  In the Olympics, how long is the marathon event in kilometers? I know it’s 26.22 miles long (26 miles 385 yds). 1.609 km 26.22 miles x km 1.000 mile 26.22 x 1.609 Now multiply Sample calculation...  In the Olympics, how long is the marathon event in kilometers? I know it’s 26.22 miles long (26 miles 385 yds). 1.609 km 26.22 miles x km 1.000 mile 42.187980 Sample calculation...  In the Olympics, how long is the marathon event in kilometers? I know it’s 26.22 miles long (26 miles 385 yds). 1.609 km 26.22 miles x km 1.000 mile 42.187980 Round to correct sig figs Sample calculation...  In the Olympics, how long is the marathon event in kilometers? I know it’s 26.22 miles long (26 miles 385 yds). 4 s.f. 1.609 km 26.22 miles x km 4 s.f. 1.000 mile 4 s.f. 42.187980 Round to correct sig figs Sample calculation...  In the Olympics, how long is the marathon event in kilometers? I know it’s 26.22 miles long (26 miles 385 yds). 4 s.f. 1.609 km 26.22 miles x km 4 s.f. 1.000 mile 4 s.f. 42.187980 Drop uncertain digits with rounding Sample calculation...  In the Olympics, how long is the marathon event in kilometers? I know it’s 26.22 miles long (26 miles 385 yds). 4 s.f. 1.609 km 26.22 miles x km 4 s.f. 1.000 mile 4 s.f. 42.19 Drop uncertain digits with rounding Sample calculation...  In the Olympics, how long is the marathon event in kilometers? I know it’s 26.22 miles long (26 miles 385 yds). 1.609 km 26.22 miles x = 42.19 km 1.000 mile Sample calculation...  In the Olympics, how long is the marathon event in kilometers? I know it’s 26.22 miles long (26 miles 385 yds). 1.609 km 26.22 miles x = 42.19 km 1.000 mile Starting Conversion Equivalent x = quantity factor(s) quantity Another calculation...  This example shows how to use the metric prefix table… How many micrograms in 4.5 x 10-5 g? Another calculation...  This example shows how to use the metric prefix table… How many micrograms in 4.5 x 10-5 g? 4.5 x 10-5 g Starting value Another calculation...  This example shows how to use the metric prefix table… How many micrograms in 4.5 x 10-5 g? 4.5 x 10-5 g mg Starting value Answer units Another calculation...  This example shows how to use the metric prefix table… How many micrograms in 4.5 x 10-5 g? 4.5 x 10-5 g mg Starting value Answer units Obtain conversion factor Another calculation...  This example shows how to use the metric prefix table… How many micrograms in 4.5 x 10-5 g? 1.0 mg 4.5 x 10-5 gx mg 10-6 g Orient so that units cancel Unit prefixes to learn... giga- (G) 109 1 Gg = 109 g mega- (M) 106 1 Mg = 106 g kilo- (k) 103 1 kg = 103 g deci- (d) 10-1 1 dg = 10-1 g centi- (c) 10-2 1 cg = 10-2 g milli- (m) 10-3 1 mg = 10-3 g micro- (m) 10-6 1 mg = 10-6 g nano- (n) 10-9 1 ng = 10-9 g pico- (p) 10-12 1 pg = 10-12g Unit prefixes to learn... giga- (G) 109 1 Gg = 109 g mega- (M) 106 1 Mg = 106 g kilo- (k) 103 1 kg = 103 g deci- (d) 10-1 1 dg = 10-1 g centi- (c) 10-2 1 cg = 10-2 g milli- (m) 10-3 1 mg = 10-3 g Aha! micro- (m) 10-6 1 mg = 10-6 g Here’s nano- (n) 10-9 1 ng = 10-9 g what we pico- (p) 10-12 1 pg = 10-12g want. Another calculation...  This example shows how to use the metric prefix table… How many micrograms in 4.5 x 10-5 g? 1.0 mg 4.5 x 10-5 gx mg 10-6 g Orient so that units cancel Another calculation...  This example shows how to use the metric prefix table… How many micrograms in 4.5 x 10-5 g? 1.0 mg 4.5 x 10-5 gx = mg 10-6 g Do the math Another calculation...  This example shows how to use the metric prefix table… How many micrograms in 4.5 x 10-5 g? 1.0 mg 4.5 x 10-5 gx = mg 10-6 g 4.5 x 10-5 1.0 x 10-6 Another calculation...  This example shows how to use the metric prefix table… How many micrograms in 4.5 x 10-5 g? 1.0 mg 4.5 x 10-5 gx = mg 10-6 g Here’s what you may need on your 4.5 x 10-5 calculator for 10-6 1.0 x 10-6 Another calculation...  This example shows how to use the metric prefix table… How many micrograms in 4.5 x 10-5 g? 1.0 mg 4.5 x 10-5 gx = mg 10-6 g 45 Another calculation...  This example shows how to use the metric prefix table… How many micrograms in 4.5 x 10-5 g? 1.0 mg 4.5 x 10-5 gx = 45 mg 10-6 g Another calculation...  This example shows how to use the metric prefix table… How many micrograms in 4.5 x 10-5 g? 1.0 mg 4.5 x 10-5 gx = 45 mg 10-6 g The answer makes sense when viewed like this... Another calculation...  This example shows how to use the metric prefix table… How many micrograms in 4.5 x 10-5 g? 1.0 mg 4.5 x 10-5 gx = 45 mg 10-6 g The answer makes sense when viewed 0.000 045 g like this... Another calculation...  This example shows how to use the metric prefix table… How many micrograms in 4.5 x 10-5 g? 1.0 mg 4.5 x 10-5 gx = 45 mg 10-6 g The answer makes sense when viewed 0.000 045 g like this... milli Another calculation...  This example shows how to use the metric prefix table… How many micrograms in 4.5 x 10-5 g? 1.0 mg 4.5 x 10-5 gx = 45 mg 10-6 g The answer makes sense when viewed 0.000 045 g like this... milli micro Another calculation...  This example shows how to use the metric prefix table… How many micrograms in 4.5 x 10-5 g? 1.0 mg 4.5 x 10-5 gx = 45 mg 10-6 g The answer makes sense when viewed 0.000 045 g like this... milli micro The Factor-Label Method  A 31.7-kg dog needs valium to suppress hysteria from 4th of July fireworks. The prepared solution needs to be administered at the rate of 2.3 mL/kg. How many mL of valium solution should be injected? Starting Conversion Equivalent x = quantity factor(s) quantity The Factor-Label Method  A 31.7-kg dog needs valium to suppress hysteria from 4th of July fireworks. The prepared solution needs to be administered at the rate of 2.3 mL/kg. How many mL of valium solution should be injected? 31.7 kg dog 73 mL soln Starting Conversion Equivalent x = quantity factor(s) quantity The Factor-Label Method  A 31.7-kg dog needs valium to suppress hysteria from 4th of July fireworks. The prepared solution needs to be administered at the rate of 2.3 mL/kg. How many mL of valium solution should be injected? 2.3 mL soln 31.7 kg dog x 73 mL soln 1.0 kg dog Starting Conversion Equivalent x = quantity factor(s) quantity The Factor-Label Method  A 31.7-kg dog needs valium to suppress hysteria from 4th of July fireworks. The prepared solution needs to be administered at the rate of 2.3 mL/kg. How many mL of valium solution should be injected? 2.3 mL soln 31.7 kg dog x 73 mL soln 1.0 kg dog Units cancel Starting Conversion Equivalent x = quantity factor(s) quantity The Factor-Label Method  A 31.7-kg dog needs valium to suppress hysteria from 4th of July fireworks. The prepared solution needs to be administered at the rate of 2.3 mL/kg. How many mL of valium solution should be injected? 2.3 mL soln 31.7 kg dog x = 73 mL soln 1.0 kg dog Do the math: 31.7 x 2.3 1.0 Starting Conversion Equivalent x = quantity factor(s) quantity The Factor-Label Method  A 31.7-kg dog needs valium to suppress hysteria from 4th of July fireworks. The prepared solution needs to be administered at the rate of 2.3 mL/kg. How many mL of valium solution should be injected? 2.3 mL soln 31.7 kg dog x = 73 mL soln 1.0 kg dog Do the math: 72.91 Starting Conversion Equivalent x = quantity factor(s) quantity The Factor-Label Method  A 31.7-kg dog needs valium to suppress hysteria from 4th of July fireworks. The prepared solution needs to be administered at the rate of 2.3 mL/kg. How many mL of valium solution should be injected? 2.3 mL soln 31.7 kg dog x = 73 mL soln 1.0 kg dog Round to 2 s.f.: 72.91 Starting Conversion Equivalent x = quantity factor(s) quantity The Factor-Label Method  A 31.7-kg dog needs valium to suppress hysteria from 4th of July fireworks. The prepared solution needs to be administered at the rate of 2.3 mL/kg. How many mL of valium solution should be injected? 2.3 mL soln 31.7 kg dog x = 73 mL soln 1.0 kg dog Round to 2 s.f.: 73 Starting Conversion Equivalent x = quantity factor(s) quantity The Factor-Label Method  A 31.7-kg dog needs valium to suppress hysteria from 4th of July fireworks. The prepared solution needs to be administered at the rate of 2.3 mL/kg. How many mL of valium solution should be injected? 2.3 mL soln 31.7 kg dog x = 73 mL soln 1.0 kg dog Round to 2 s.f.: 73 Starting Conversion Equivalent x = quantity factor(s) quantity The Factor-Label Method  A 31.7-kg dog needs valium to suppress hysteria from 4th of July fireworks. The prepared solution needs to be administered at the rate of 2.3 mL/kg. How many mL of valium solution should be injected? 2.3 mL soln 31.7 kg dog x = 73 mL soln 1.0 kg dog Starting Conversion Equivalent x = quantity factor(s) quantity Chained calculations...  Sometimes it is necessary to string several conversion factors together to get from one set of units to another  The same strategy holds -- arrange each term so that units cancel and work towards those associated with the final answer Chained calculations...  Let’s develop the relationship between hectares and acres  A hectare is the metric unit used to describe the area of a forest stand or the habitat used by a species of wildlife  A hectare is a square measuring 100 meters on a side Chained calculations... (100 m) 2 Chained calculations... (100 m) 2 Look up conversion factors. A useful start is: 1.00 m = 3.28 ft (I’ll always provide these in the problem if they’re “unusual”) Chained calculations... (3.28 ft) 2 (100 m) 2 x (1.00 m) 2 Include it twice since meters appears twice, i.e., it’s squared Chained calculations... (3.28 ft) 2 (100 m) 2 x (1.00 m) 2 Cancel meters2 Chained calculations... (3.28 ft) 2 (100 m) 2 x (1.00 m) 2 Find next conversion factor 1.0000 acre = (208.71 ft)2 Chained calculations... (3.28 ft) 2 (100 m) 2 x (1.00 m) 2 1.0000 acre x (208.71ft)2 Add the new factor to the chain Chained calculations... (3.28 ft) 2 (100 m) 2 x (1.00 m) 2 1.0000 acre x (208.71ft)2 Cancel ft 2 Chained calculations... (3.28 ft) 2 (100 m) 2 x (1.00 m) 2 1.0000 acre x (208.71ft)2 Do the math Chained calculations... (3.28 ft) 2 (100 m) 2 x (1.00 m) 2 1.0000 acre x (208.71ft)2 Do the math 100 x 100 x 3.28 x 3.28 x 1.0000 1.00 x 1.00 x 208.71 x 208.71 Chained calculations... (3.28 ft) 2 (100 m) 2 x (1.00 m) 2 1.0000 acre x (208.71ft)2 Do the math 100 x 100 x 3.28 x 3.28 x 1.0000 Ignore 1.00 x 1.00 x 208.71 x 208.71 the 1’s Chained calculations... (3.28 ft) 2 (100 m) 2 x (1.00 m) 2 1.0000 acre x (208.71ft)2 Do the math 100 x 100 x 3.28 x 3.28 x 1.0000 Ignore 1.00 x 1.00 x 208.71 x 208.71 the 1’s Chained calculations... (3.28 ft) 2 (100 m) 2 x (1.00 m) 2 1.0000 acre x (208.71ft)2 Do the math 100 x 100 x 3.28 x 3.28 Ignore 208.71 x 208.71 the 1’s Chained calculations... (3.28 ft) 2 (100 m) 2 x (1.00 m) 2 1.0000 acre x (208.71ft)2 Do the math 100 x 100 x 3.28 x 3.28 = 2.47 208.71 x 208.71 Chained calculations... (3.28 ft) 2 (100 m) 2 x (1.00 m) 2 1.0000 acre x (208.71ft)2 Do the math = 2.47 acre Chained calculations... (3.28 ft) 2 (100 m) 2 x (1.00 m) 2 1.0000 acre x (208.71ft)2 = 2.47 acre Chained calculations...  Note we now have a new conversion factor available! 1.00 ha = 2.47 acres A Hectare calculation...  A healthy stand of Pinus ponderosa has 250 trees per acre. What is the equivalent stand density in terms of trees per hectare? The Factor-Label Method  Uses conversion factors to go between unit systems Starting Conversion Equivalent x = quantity factor(s) quantity Chained calculations...  Note we now have a new conversion factor available! 1.00 ha = 2.47 acres  Let’s use it to do a calculation Jane (G. Wiz’s wife) says gets messed up all the time by her staff writers... A Hectare calculation...  A healthy stand of Pinus ponderosa has 250 trees per acre. What is the equivalent stand density in terms of trees per hectare? A healthy stand of ponderosa in Primm Meadow up Gold Creek A Hectare calculation...  A healthy stand of Pinus ponderosa has 250 trees per acre. What is the equivalent stand density in terms of trees per hectare? Note starting units A Hectare calculation...  A healthy stand of Pinus ponderosa has 250 trees per acre. What is the equivalent stand density in terms of trees per hectare? 250 trees 1 acre Note starting units A Hectare calculation...  A healthy stand of Pinus ponderosa has 250 trees per acre. What is the equivalent stand density in terms of trees per hectare? 250 trees 1 acre Note starting units A Hectare calculation...  A healthy stand of Pinus ponderosa has 250 trees per acre. What is the equivalent stand density in terms of trees per hectare? 250 trees 1 acre Now note final units A Hectare calculation...  A healthy stand of Pinus ponderosa has 250 trees per acre. What is the equivalent stand density in terms of trees per hectare? 250 trees 1 acre Now note final units A Hectare calculation...  A healthy stand of Pinus ponderosa has 250 trees per acre. What is the equivalent stand density in terms of hectares? 250 trees trees = 1 acre ha Now note final units A Hectare calculation...  A healthy stand of Pinus ponderosa has 250 trees per acre. What is the equivalent stand density in terms of trees per hectare? 250 trees trees = 1 acre ha Now note final units A Hectare calculation...  A healthy stand of Pinus ponderosa has 250 trees per acre. What is the equivalent stand density in terms of trees per hectare? 250 trees trees = 1 acre ha Determine units to get answer A Hectare calculation...  A healthy stand of Pinus ponderosa has 250 trees per acre. What is the equivalent stand density in terms of trees per hectare? 250 trees 2.47 acre trees x = 1 acre 1.00 ha ha Determine units to get answer Chained calculations...  Note we now have a new conversion factor available! 1.00 ha = 2.47 acres  Let’s use it to do a calculation Jane (G. Wiz’z wife) says gets messed up all the time by her staff writers... A Hectare calculation...  A healthy stand of Pinus ponderosa has 250 trees per acre. What is the equivalent stand density in terms of trees per hectare? 250 trees 2.47 acre trees x = 1 acre 1.00 ha ha Next, use our new conversion factor! A Hectare calculation...  A healthy stand of Pinus ponderosa has 250 trees per acre. What is the equivalent stand density in terms of trees per hectare? 250 trees 2.47 acre trees x = 1 acre 1.00 ha ha See, acres cancel out. A Hectare calculation...  A healthy stand of Pinus ponderosa has 250 trees per acre. What is the equivalent stand density in terms of trees per hectare? 250 trees 2.47 acre trees x = 1 acre 1.00 ha ha See, acres cancel out. A Hectare calculation...  A healthy stand of Pinus ponderosa has 250 trees per acre. What is the equivalent stand density in terms of trees per hectare? 250 trees 2.47 acre trees x = 1 acre 1.00 ha ha 250 x 2.47 A Hectare calculation...  A healthy stand of Pinus ponderosa has 250 trees per acre. What is the equivalent stand density in terms of trees per hectare? 250 trees 2.47 acre trees x = 1 acre 1.00 ha ha 617.5 A Hectare calculation...  A healthy stand of Pinus ponderosa has 250 trees per acre. What is the equivalent stand density in terms of trees per hectare? 2 s.f. 250 trees 2.47 acre 620 trees x = 1 acre 1.00 ha ha 617.5 A Hectare calculation...  A healthy stand of Pinus ponderosa has 250 trees per acre. What is the equivalent stand density in terms of trees per hectare? 250 trees 2.47 acre 620 trees x = 1 acre 1.00 ha ha A Hectare calculation...  A healthy stand of Pinus ponderosa has 250 trees per acre. What is the equivalent stand density in terms of trees per hectare? 250 trees 2.47 acre 620 trees x = 1 acre 1.00 ha ha http://feis-crs.org/beta/ Chemistry: The Study of Change Lessons Learned Distinguish between physical and chemical changes. Especially with heat Use scientific notation in calculations Understand significant figure limitations Chemistry: The Study of Change Lessons Learned Perform conversions from one unit to another including temperatures among Fahrenheit, Celsius and Kelvin Use metric units and prefixes for mass, length, volume, etc. Apply the factor-label method

CHE101_01_Summer21 PDF - General Chemistry

Document Details

Tags

Related

Summary

Full Transcript