Sci 9 Unit B T3&4 PPT PDF

3.1 – NAMING COMPOUNDS ⦿ Each element has a chemical name ⦿ The combination of elements to form compounds has a chemical name and a chemical formula ⦿ The chemical formula identifies which elements and how many of each are in the compound Aluminum Oxide...

3.1 – NAMING COMPOUNDS ⦿ Each element has a chemical name ⦿ The combination of elements to form compounds has a chemical name and a chemical formula ⦿ The chemical formula identifies which elements and how many of each are in the compound Aluminum Oxide Al2O3 2 Aluminum; 3 Oxygen  COMBINING ELEMENTS TO MAKE COMPOUNDS ⦿ Ie: ethanol (C2H5OH) has 2 carbon atoms, 6 hydrogen atoms and 1 oxygen atom  COMBINING ELEMENTS TO MAKE COMPOUNDS ⦿ Table salt ⚫ Chemical name: sodium chloride ⚫ Chemical formula: NaCl ⚫ Elements: 1 sodium atom, 1 chlorine atom ⦿ Baking Soda ⚫ Chemical name: sodium bicarbonate ⚫ Chemical formula: NaHCO3 ⚫ Elements: 1 sodium atom, 1 hydrogen atom, 1 carbon atom, 3 oxygen atoms  COMBINING ELEMENTS TO MAKE COMPOUNDS ⦿ Glucose ⚫ Chemical name: glucose ⚫ Chemical formula: C6H12O6 ⚫ Elements: 6 carbon atoms, 12 hydrogen atoms, 6 oxygen atoms NAMING CHEMICAL COMPOUNDS ⦿ A standardized chemical naming system, or nomenclature, is used ⦿ The IUPAC (International Union of Pure and Applied Chemistry) is responsible for determining the appropriate name for each compound ⦿ The metal name is always first  INTERPRETING CHEMICAL NAMES AND FORMULAS FROM COMPOUNDS ⦿ If you know the formula for a compound you can determine its chemical name – if you know its name, you can determine its formula ⦿ Write the chemical formula as determined by the name of the compound. (If a poly atomic ion is part of the formula, keep the poly-atomic ion intact)  INTERPRETING CHEMICAL NAMES AND FORMULAS FROM COMPOUNDS ⦿ Aluminum oxide ⚫ 2 - Al ⚫ 3-O ⚫ Al2O3 ⦿ Calcium nitrite ⚫ 1 - Ca ⚫ 2 - NO2 Polyatomic Ion ⚫ Ca(NO2)2 ⦿ Sodium Chloride ⚫ 1 - Na ⚫ 1 – Cl ⚫ NaCl  INTERPRETING CHEMICAL NAMES AND FORMULAS FROM COMPOUNDS ⦿ If the compound contains a metal, it is ionic ⦿ If the compound does not contain a metal, it is molecular  INDICATING THE PHYSICAL STATE OF A COMPOUND ⦿ Another common notation added to chemical compounds indicates the state of the chemical at room temperature ⚫ NaCl(s) = solid ⚫ H2O(l) = liquid ⚫ CH4(g) = gas ⦿ For substances dissolved in water ⚫ NaCl(aq) = aqueous solutions ACHIEVEMENT TEST PREP Which of the following rows identifies both the elements and number of atoms that are present in one molecule of C6H12O6?  3.2 – IONIC COMPOUNDS ⦿ Sodium Chloride (table salt) – NaCl – is an ionic compound ⦿ Ionic compounds are pure substances formed as a result of the attraction between particles of opposite charges, called ions. ⦿ Formation of NaCl  IONIC COMPOUNDS ⦿ When the ionic compound is dissolved in water, the metal (Na) and non-metal (Cl2) form an aqueous solution of ions ⦿ An ion is an atom or group of atoms that has become electrically charged through a loss or gain of electrons  IONIC COMPOUNDS ⦿ A superscript (+) or a (–) are used to indicate the charge - Na+ and Cl- ⦿ Some ions can also form when certain atoms of elements combine: called polyatomic ions (poly meaning “many”) ⦿ Polyatomic ions are a group of atoms acting as one ⚫ Carbonate = CO32- ⚫ Sulfate = SO42- PROPERTIES OF IONIC COMPOUNDS High Melting Point Good Electrical Conductivity Distinctive Crystal Shape Solid at Room Temperature NAMING IONIC COMPOUNDS ⦿ 1. The chemical name of the metal or positive ion goes first, followed by the name of the non-metal or negative ion. ⦿ 2. The name of the non-metal negative ion changes its ending to ide. ⚫ One exception – Where negative ions are polyatomic ions, the name remains unchanged. Metal Non-Me Metal Non-Me tal-ide tal-ide NAMING IONIC COMPOUNDS ⦿ Elements with more than one ion charge use a roman numeral in its chemical name to clearly show which ion is being used. CuSO4 (Copper II Sulfate) Ionic Bonding Simulation https://simbucket.com/chemthinkserver/ch emthink/index.html?ib  EXAMPLES ⦿ Na+ and Cl- ⚫ Name the metal first ○ Sodium ⚫ Name the non-metal second and change it’s ending to –ide ○ Chloride ⚫ ***Drop and swap the charges for chemical formula*** + - ○ Sodium chloride = NaCl Na Cl  EXAMPLES ⦿ Ca2+ and Cl- ⚫ Name the metal first ○ Calcium ⚫ Name the non-metal second ○ Chloride ⚫ ***Drop and swap the charges for chemical formula*** ○ Calcium chloride = CaCl2 2+ - Ca Cl  EXAMPLES ⦿ Fe3+ and O2- ⚫ Name the metal first ○ Iron ⚫ Name the non-metal second ○ Oxide ⚫ Use a roman numeral to indicate which iron was used ⚫ ***Drop and swap the charges for chemical formula*** 3+ 2- ○ Iron (III) oxide = Fe2O3 Fe O ION CHARGES AND THE PERIODIC TABLE Patterns Ion Charge Alkali Metals +1 Halogens -1 Generally elements in a group all have the same ion charge (most consistent at either end of the table) Bell Ringer #6 ⦿ What are the properties of ionic compounds? ⦿ Write the chemical name and formula of the following combinations: ⚫ Magnesium and Phosphorus ⚫ Iron (II) and Fluorine ⚫ Potassium and Bromine 3.3 – MOLECULAR COMPOUNDS ⦿ When non-metals combine, they produce a pure substance called a molecule, or molecular compound ⦿ They can be solids, liquids, or gases at room temperature ⚫ sugar = C12H22O11(s) ⚫ water = H20(l) ⚫ hydrogen = H2(g) PROPERTIES OF MOLECULAR COMPOUNDS Low Melting Point Low Boiling Point Good Insulators Poor Conductors Distinct Crystal Shape WRITING FORMULAS FOR MOLECULAR COMPOUNDS ⦿ Rules: ⚫ 1. The first element in the compound uses the element name (just like the ionic compounds do) ⚫ 2. The second element has a suffix – ide – (like the ionic compounds)  WRITING FORMULAS FOR MOLECULAR COMPOUNDS ⚫ 3. When there is more than 1 atom in the formula, a prefix is used which tells how many atoms there are: Number of Atoms Prefix 1 mono 2 di 3 tri 4 tetra 5 penta 6 hexa 7 hepta  WRITING FORMULAS FOR MOLECULAR COMPOUNDS ⚫ 4. Exception to #3 above – when the first element has only 1 atom the prefix mono is not used. ⚫ Examples: ○ CO2 carbon dioxide ○ CCl4 carbon tetrachloride  EXAMPLES ⦿ Using the above rules, molecular compounds are named using this format: ⚫ Prefix + First Element ⚫ Prefix + Second Element (with ‘ide’ ending) ○ CO2 carbon dioxide ○ N2O dinitrogen monoxide ○ N2O3 dinitrogen trioxide ○ NF3 nitrogen trifluoride ○ CCl4 carbon tetrachloride ○ PF5 phosphorus pentafluoride ACHIEVEMENT TEST PREP When two i elements are combined, ii compound is formed. The statement above is completed by the information in row ACHIEVEMENT TEST PREP ⦿ What is the chemical name of a molecular substance that is composed of one carbon atom and four chlorine atoms? ⚫ A. Carbon tetrachlorine ⚫ B. Carbon tetrachloride ⚫ C. Carbon chlorine ⚫ D. Carbon chloride  GIZMO ⦿ Ionic and Molecular Compounds General Outcome 4 Students will apply simplified chemical nomenclature in describing elements, compounds and chemical reactions Specific Outcomes ⦿ describe familiar chemical reactions, and represent these reactions by using word equations and chemical formulas and by constructing models of reactants and products General Outcome 2 Students will describe and interpret patterns in chemical reactions Specific Outcomes ⦿ identify and evaluate dangers of caustic materials and potentially explosive reactions ⦿ observe and describe evidence of chemical change in reactions between familiar materials, by: − describing combustion, corrosion and other reactions involving oxygen − observing and inferring evidence of chemical reactions between familiar household materials ⦿ distinguish between materials that react readily and those that do not ⦿ observe and describe patterns of chemical change, by: − observing heat generated or absorbed in chemical reactions, and identifying examples of exothermic and endothermic reactions − identifying conditions that affect rates of reactions ⦿ identifying evidence for conservation of mass in chemical reactions, and demonstrating and describing techniques by which that evidence is gathered 4.1 – CHEMICAL REACTIONS ⦿ A chemical reaction takes place when two or more substances combine to form new substances ⦿ Launching a space shuttle involves almost 1 500 000 L of liquid hydrogen and 545 000 L of liquid oxygen combining to form water… enough energy is released to put the shuttle into orbit around Earth  CHEMICAL REACTIONS ⦿ The materials at the start of a reaction are called reactants ⦿ The new materials produced by the reaction are called the products reactant reactant product product (yields)  IDENTIFY PRODUCTS & REACTANTS ⦿ Campfire ⚫ Reactants ○ Wood ○ Oxygen ⚫ Products ○ CO2 ○ Water ○ Energy Released (heat) Wood + Oxygen 🡪 CO2 + Water + Energy Released (yields) ⦿ Do “Give it a Try” on page 158 ⦿“Give it a Try” on page 158 Reaction 1 - Reactants: Products: Word Equation: _________________________________________________________________ Reaction 2 – Reactants: Products: Word Equation: _________________________________________________________________ Reaction 3 – Reactants: Products: Word Equation: ________________________________________________________________ EVIDENCE OF CHEMICAL CHANGE Color Formation Change of an Odor Formation Release or of a Solid Absorption or Gas of Heat  EXOTHERMIC & ENDOTHERMIC REACTIONS ⦿ Exothermic Reaction – A chemical reaction that releases heat ⚫ For example – a fireplace (heat is given off) ‘Exit’ ⦿ Endothermic Reaction – A chemical reaction that absorbs heat ⚫ For example – cold packs (heat is absorbed) Global News – Science Teacher Demos ⦿ https://globalnews.ca/video/3970069/co ol-science-how-do-cold-packs-work  CHEMICAL CHANGES INVOLVING OXYGEN Combustion Corrosion Cellular Respiration  COMBUSTION ⦿ A chemical reaction that occurs when oxygen reacts with a substance to form a new substance and give off energy ⦿ In burning, wood reacts with oxygen to give off heat and light and produce carbon dioxide and water  CORROSION ⦿ The slow chemical change that occurs when oxygen in the air reacts with a metal ⦿ A common example of corrosion is rusting ⦿ Rusting occurs when iron reacts with oxygen to form iron oxide  CELLULAR RESPIRATION ⦿ A chemical reaction that takes place in the cells in your body ⦿ Food (glucose) reacts with oxygen to produce energy, water, and carbon dioxide Achievement Test Prep 4.2 – CONSERVATION OF MASS IN CHEMICAL REACTIONS ⦿ The Law of Conservation of Mass: matter is not created or destroyed in a chemical reaction ⦿ In a closed system (no additional material is allowed to enter or leave) the total mass of the products is always the same as the total mass of the reactants  CONSERVATION OF MASS IN CHEMICAL REACTIONS ⦿ In an open system (gas or energy is released into the surroundings) the total mass of the products is sometimes less than the total mass of the reactants ⦿ For example: Adding 10g of Alka-Seltzer to 100g of water results in a mass of 106g, because 4g of carbon dioxide gas was given off Watch Videos 1 and 2 1 - Alka-Seltzer to water experiment 2 - Law explained Video 1 Video 2 Achievement Test Prep 4.3 Factors Affecting the Rate of a Chemical Reaction ⦿ The four factors that can affect the rate of a chemical reaction are: ⚫ The presence of a catalyst ⚫ The concentration of the reactants ⚫ The temperature of the reactants ⚫ The surface area of the reactants Catalysts ⦿ Catalysts – substances that help a reaction proceed faster ⦿ The most common catalyst found in our bodies are enzymes. ⦿ Enzymes help break down food in our bodies at a faster rate Concentration ⦿ The greater the concentration of the reactants, the faster the reaction. ⦿ The increased concentration of the reactants means that there are more atoms of each reactant available to react. Temperature ⦿ The more heat added to the reactants, the faster the reaction. ⦿ The added heat causes the atoms of each reactant to move faster, which increases the chances of them colliding with each other. Surface Area ⦿ The greater the surface area of the reactants, the more area is available for reaction. ⦿ Breaking a substance into smaller pieces would increase the surface area causing the reaction to proceed faster.