Unit 1 Chemistry Past Paper PDF

Unit 1 Introduction to Matter, Measurement, and Experimental Analysis Date Topic Assignments and Due Dates M 8/19 (Anchor) Welcome to Chemistry! Safety Agreement Completed O...

Unit 1 Introduction to Matter, Measurement, and Experimental Analysis Date Topic Assignments and Due Dates M 8/19 (Anchor) Welcome to Chemistry! Safety Agreement Completed Online Tues. 8/20 (Blue) Safety Walkthrough Wed. 8/21 (Red) Properties and Changes of Matter Physical and Chemical Changes Lab Thurs. 8/22 (Blue) Safety Quiz Fri. 8/23 (Red) Properties: Metal v. Nonmetal Copper Wire Density Lab Mon. 8/26 (Red) Measurement and Significant Figures Tues. 8/27 (Blue) Finish Copper Wire Density Lab Wed. 8/28 (Red) Percent Error Calculations Glassware Lab due Sept. 5-6 Thurs. 8/29 (Blue) Accuracy of Glassware Lab *Common Lab* Tues. 9/3 (Blue) Dimensional Analysis Wed. 9/4 (Red) Thurs. 9/5 (Blue) Dimensional Analysis Activity Dimensional Analysis Activity due end of class Fri. 9/6 (Red) Classification of Matter M 9/9 (Anchor) Naming Pure Substances Tues. 9/10 (Blue) Naming and Classification Practice Wed. 9/11 (Red) Separating Mixtures Thurs. 9/12 (Blue) Separation of a Mixture Lab Fri. 9/13 (Red) M 9/16 (Anchor) Review Tues. 9/17 (Blue) Wed. 9/18 (Red) Unit 1 Test  Year-Long Scientific and Engineering Practices Ask Questions and Define Problems Ask questions that arise from careful observation of phenomena, etc. Determine which questions can be investigated within the school lab Make hypotheses that specify what happens to a dependent variable Generate hypotheses based on research and scientific principles Define design problems: development of a process with components, etc. Identify key issues & problems suitable for investigation & discourse Plan and Carry Out Investigations Individually and collaboratively plan and conduct investigations Plan/conduct investigations or test design solutions in a safe manner Select/use appropriate tools & technology to collect/record/etc. Data Interpret, Analyze, and Evaluate Data Record/present data in organized format: mathematical/algebraic forms Use data in models, explanations, or testing solutions Solve problems using mathematical manipulations: SI, notation, etc. Analyze data to make valid and reliable claims or a design solution Analyze data graphically and use graphs to make predictions Differentiate between accuracy and precision of measurements Consider limitations of data analysis when analyzing and interpreting Analyze data to optimize a design Construct and Critique Conclusions and Explanations Construct/revise explanations based on valid and reliable evidence Apply scientific ideas, principles, evidence to provide an explanation Compare/evaluate competing arguments in light of current explanations Construct arguments or counterarguments based on data and evidence Differentiate between scientific hypothesis, theory, and law Develop and Use Models Evaluate the merits and limitations of models Develop, revise, use models to illustrate or predict relationships Use models and simulations to visualize, represent, interpret, etc. Develop a timeline that traces the development of a scientific idea Obtain, Evaluate, and Communicate Information Compare, integrate, and evaluate sources of information Gather, read, evaluate scientific information & assess credibility Communicate scientific/technical information or a design process Cite the contributions made by individual scientists and/or by a team Know & follow current standards for ethical scientific investigations Present their own investigations and defend their conclusions 2  Unit 1 Matter, Measurement, and Experimental Analysis Enduring Understandings Matter is conserved because atoms are conserved in chemical and physical processes. The law of conservation of matter (mass) states that, regardless of how substances within a closed system are changed, the total mass remains the same. The products formed in a chemical reaction have different properties than the original reactants. Chemical formulas are used to represent compounds. Subscripts represent the relative number of each type of atom in a molecule or formula unit. Matter consists of atoms held together by electromagnetic forces and exists as different substances which can be utilized based on their properties. Intramolecular bonds form between atoms to achieve stability. Covalent bonds involve the sharing of electrons between nonmetal atoms. Ionic bonds involve the transfer of electrons between metal and nonmetal ions. Physical properties refer to the condition or quality of a substance that can be observed or measured without changing the substance’s composition. Chemical properties refer to the ability of a substance to undergo chemical reaction and form a new substance. Essential Knowledge and Skills Distinguish between chemical and physical properties Distinguish between pure substances/mixtures, homo/heterogeneous mixtures Classify elements as metals, metalloids, or nonmetals Name chemical formulas for binary covalent and ionic compounds Recognize the relationship between types of compound, naming patterns, and the use of “formula units” versus “molecules” Calculate the percent yield and percent error for a given process Describe the purpose and implementation of chromatography, distillation, filtration, decanting, magnetic separation, evaporation, and centrifugation for separating mixtures 3  FCPS High School Science Student Safety Agreement Science is a laboratory class that conducts hands-on investigations. You will be doing many laboratory investigations that require the use of potentially hazardous chemicals, materials, and equipment. Safety in the science classroom is the #1 priority for students, teachers, and parents. To ensure a safe science classroom, a list of rules has been provided to you in this student safety agreement. These rules must be followed at all times. Two copies of the agreement are provided. One copy must be signed by both you and a parent or guardian before you can participate in the laboratory. The second copy is to be kept in your science notebook as a constant reminder of the safety rules. General physician about working in the lab if you 1. Follow all instructions and directions have a medical condition. carefully. Read all labels and equipment instructions before conducting investigations Clothing and Personal Protective Equipment in the lab. 17. Goggles must be worn at all times when 2. Act responsibly in the lab at all times. Do not working with chemicals, heat, and glassware. roughhouse or joke around in the lab. 18. Appropriate dress is required for 3. No eating or drinking in the lab. Plumbing participation in lab activities (see below). fixtures/faucets in laboratory classrooms 19. Lab aprons are provided and should be and prep rooms may contain smalls amount used for investigations in the lab involving of lead and are not intended for drinking chemicals, dissections, biological agents, water. They can be safely used for lab and heat. experiments, hand, and equipment washing, but should never be used for drinking water Accidents and Injuries to include water bottle filling, tea, coffee, 20. Promptly report ALL accidents, injuries, and food prep, etc. spills to your teacher. 4. Never work unsupervised in the lab. 5. Do not touch any lab equipment or materials Handling Chemicals until you have been instructed to do so. 21. Long hair, loose clothing, and jewelry should be 6. Unauthorized experiments are not pulled back. Closed-toe shoes are required. permitted. Do not alter your lab procedure 22. A fume hood must be used for chemicals that without the approval of your teacher. need ventilation. 7. Keep your lab area clean and clutter free before, 23. When cleaning up after a lab: during, and after an investigation. a. Clean your lab station. 8. Avoid touching your eyes, nose, or mouth b. Handle waste chemicals as when conducting an investigation in the lab. instructed. 9. Know the location and procedure for c. Wash hands with soap and water. operating all safety equipment in the lab. 24. Do not touch or taste any chemicals. If 10. Notify your teacher if you notice anything instructed to smell chemicals, waft the that may be unsafe. vapors from a container. Do not directly 11. Handle all lab waste material as instructed. smell chemicals from any container. 12. Wash hands with soap and water before 25. Only use a rubber bulb or pipette pump to leaving the lab when appropriate. fill a pipette. Never use your mouth. 13. Do not go in the lab prep room or storage 26. View test tube contents from the side, not room without your teacher’s permission. above. Follow your teacher-demonstrated 14. Know the lab procedure for fire drills or technique for mixing chemicals in a test other lab interruptions: turn heating tube. elements off, close all containers, and shut 27. Spills must be cleaned up appropriately. In off gas. case of a spill, report it to your teacher 15. Be careful when using sharp objects in the immediately. lab. Always carry sharp objects by the 28. Acids and bases should be handled with handle with the sharp end pointing away caution. When diluting an acid, always add from yourself and others. the acid to the water. 16. Inform your teacher about any medical 29. In case of injury, notify your teacher. condition(s) that may affect your ability to 30. If a chemical gets on your skin, rinse it with work in the lab. Always check with your water. Adapted from Flinn Scientific Student Safety Contract 2015 with permission. FCPS August 2022 1 4  31. If a chemical is splashed into your eyes, 46. Discharge electrostatic equipment only as flush your eyes in the eyewash station for instructed. 20 minutes. If wearing contact lenses, 47. Beware of sharp edges on all lab equipment remove them as soon as possible. and use care in working with these objects. 48. Handle heavy objects carefully at all times. Handling Glassware 49. Never look directly into a laser or point a 32. Always check glassware for cracks or chips laser at a person. before use. Never use damaged Handling Biological Material glassware. 33. Report any broken or cracked glassware to 50. Slide and petri dish preparation require the your teacher. Broken glass should be use of goggles. Goggles may be disposed of as instructed. temporarily removed when viewing specimens through microscopes, but should Heating and Using an Open Flame be worn at all other times when working with 34. Long hair, loose clothing, and jewelry should be biological agents. pulled back before using heat or open flames. 51. Gloves are required to be worn when using 35. Never leave an open flame or anything preserved specimens. being heated unattended. 52. Clean all work surfaces and wash your 36. Stay focused and attentive at all times when hands with soap and water after performing using an open flame. Never reach over an experiments involving preserved or live open flame. specimens or bacteria. 37. When heating a test tube, use a test tube 53. All biological materials should be disposed clamp and always point the open end of the of as instructed. test tube away from yourself and others. Student Agreement: 38. Do not heat flammable liquids with an open I agree to follow all of the safety rules of this agreement. flame. Never dispense flammable liquids I realize that I am responsible for following these rules to anywhere near an open flame or heat ensure my own safety and the safety of others. I will source. work with my teacher and classmates to maintain a safe 39. Glassware and metal stay hot long after lab environment. I will follow the oral and written heating and look the same as cool instructions provided by my teacher. I am aware that any equipment. Set them aside to cool on an violation of this safety agreement that results in unsafe insulated surface before handling. lab conditions may result in disciplinary action taken in 40. When using a hot plate, do not touch the accordance with the SR&R. heating surface. 41. Unplug the hot plate when finished and set Printed Student Name:________________________________________ aside to cool. 42. In case of injury from heat, notify your Student teacher. Signature: ____________________________________ a. Cool burns by placing the affected area under cold water. Date: ______________________________________ Handling Electrical and Other Equipment Parent/Guardian Agreement: 43. Always use the plug - not the cord - to I have read the safety rules of this agreement and I am remove an electrical plug from the socket. aware of measures taken to provide a safe lab Be sure that your hands are dry when environment for my child. I will direct my child to uphold touching an electrical switch, plug or wall this agreement and follow these rules in the lab. socket. 44. Visually inspect equipment before plugging Printed Parent/ Guardian Name:________________________________ it into a wall socket. Never use equipment with frayed wires, exposed wires, or loose Parent/ connections. Guardian Signature: ____________________________ 45. Report damaged equipment immediately to your teacher. Date: ___________________________________________ Adapted from Flinn Scientific Student Safety Contract 2015 with permission. FCPS August 2022 2 5 Safety Reference 1-800-452-1261 flinnsci.com How to Read A Safety Data Sheet (SDS) Safety Data Sheets (SDS) are an important requirement of the OSHA Hazard Communication Standard. SDS are essential documents that are used to inform employees, students, and the general public about how materials can be safely handled, used, and stored. Since Flinn provides chemicals only to schools, we have written Flinn SDS specifically for teachers and their students. Using clear and straightforward language, each Flinn SDS provides all the relevant safety and hazard information in a consistent, useful, and easy-to-read two-page format. Flinn SDS follow the Globally Harmonized System of Classification and Labeling of Chemicals (GHS). The 16 sections are divided into four major areas, each designed to answer a specific question. What is the material and what do I need to know immediately in an emergency? Sections 1–3. LINN CIENTIFIC NC SDS #: 181.00 Safety Data Sheet (SDS) Revision Date: September 25, 2013 A It is important that the chemical name on the label match the name on the SDS. Many SECTION 1 — CHEMICAL PRODUCT AND COMPANY IDENTIFICATION chemicals have similar names, but very different n-Butyl Alcohol properties. A Flinn Scientific, Inc. P.O. Box 219 Batavia, IL 60510 (800) 452-1261 C D Pictograms CHEMTREC Emergency Phone Number: (800) 424-9300 Signal Word DANGER B The most important section! Provides an SECTION 2 — HAZARDS IDENTIFICATION over­view of the physical and health hazard risks Hazard class: Flammable liquids (Category 3). Flammable liquid and vapor (H226). Keep away from heat, associated with using the material. sparks, open flames, and hot surfaces. No smoking (P210). B Hazard class: Acute toxicity, oral (Category 4). Harmful if swallowed (H302). Do not eat, drink or smoke when C Signal words, either Danger or Warning, using this product (P270). heighten the awareness of the relative risk when Hazard class: Skin corrosion or irritation (Category 2). Causes skin irritation (H315). using certain chemicals. Danger is the more severe warning! Hazard class: Serious eye damage/eye irritation (Category 1). Causes serious eye damage (H318). Hazard class: Specific target organ toxicity, single exposure; respiratory tract irritation (Category 3). May cause D Eight pictograms exist in the GHS classifica- respiratory irritation (H335). tion scheme to call attention to physical and health Hazard class: Specific target organ toxicity, single exposure; Narcotic effects (Category 3). May cause hazards. See page 1158 for more information about drowsiness or dizziness (H336). Avoid breathing mist, vapors or spray (P261). GHS pictograms. SECTION 3 — COMPOSITION, INFORMATION ON INGREDIENTS Formula Component Name CAS Number Formula Weight Concentration E This section includes the formula, formula n-Butyl alcohol 71-36-3 CH3(CH2)2CH2OH 74.12 weight, concentration, and CAS#. The CAS# is E the single identifying number for each specific substance. CAS# should match the CAS# on the bottle label. Synonym: 1-Butanol; n-Butanol SECTION 4 — FIRST AID MEASURES Call a POISON CENTER or physician if you feel unwell (P312). F If inhaled: Remove victim to fresh air and keep at rest in a position comfortable for breathing (P304+P340). If in eyes: Rinse cautiously with water for several minutes. Remove contact lenses if present and easy to do. Continue rinsing What should I do if a hazardous (P305+P351+P338). situation occurs? If on skin (or hair): Immediately remove all contaminated clothing. Rinse skin with water (P303+P361+P353). If swallowed: Rinse mouth. Call a POISON CENTER or physician if you feel unwell (P302+P301+P312). Sections 4–6. SECTION 5 — FIRE FIGHTING MEASURES Class 1C flammable liquid. G NFPA CODE F Seek medical attention. These first-aid Flash point: 37 oC Flammable limits: Lower: 1.4% Upper: 11.2% Autoignition Temperature: 343 oC H-2 When heated to decomposition, may emit CO and CO2. F-3 H measures are only meant for imme­diate first aid In case of fire: Use triclass dry chemical fire extinguisher (P370+P378). R-0 and should always be followed up with profes- sional medical care. The CAS# is the single identifying number for each specific substance. SECTION 6 — ACCIDENTAL RELEASE MEASURES CAS# should match the CAS# on the bottle label. Remove all ignition sources and ventilate area. Contain the spill with sand or other inert absorbent material and deposit in a sealed bag or container. See Sections 8 and 13 for further information. I G This section is written for the firefighter. Flash © 2013 Flinn Scientific, Inc. All Rights Reserved. PAGE 1 OF 2 point (the lowest temperature at which enough vapor is present to form an ignitable mixture with air); upper and lower flammable limits; and the auto ignition temperature (AIT) are common prop- erties included in this section. H The NFPA code is a numerical code estab- I How to clean up a spill. Always remove lished by the National Fire Protection Association. unprotected personnel from area and make sure It rates the substance under fire conditions in four all students are safe. Contain the spill with sand categories. Health, Flammability, Reactivity, or absorbent materials. and unusual reactivity: 4 is a severe hazard, 0 is no hazard. HOW TO READ A SAFTEY DATA SHEET (SDS) continued on next page. 6 “Your Safer Source for Science Supplies” How to Read A Safety Data Sheet (SDS) How to Read A Safety Data Sheet (SDS), continued Each Flinn SDS follows the same format and the information is always found in the same location, making it a valuable resource in the event of an emergency. With your first chemical order of the year, every teacher will receive a CD from Flinn Scientific containing all of our SDS. You may also request another CD at any time. Flinn SDS are updated on a regular basis, guaranteeing the most up-to-date safety information possible. Flinn sells a complete SDS Library in two versions, a hard copy version in two binders (Catalog No. AP7703) or as part of the Flinn Online Chemventory program. For a more detailed description of the Flinn Online Chemventory program (Catalog No. SE3000), please refer to the Flinn Scientific Catalog/Reference Manual. For our customers’ convenience, Flinn has also placed a free complete set of SDS on our website. Simply go to www. flinnsci.com and click on the Free SDS button—individual SDS are easy to find and copies may be printed from your computer. How can I prevent hazardous situations from occurring? FLINN SCIENTIFIC, INC. Sections 7–11. Safety Data Sheet n-Butyl Alcohol SDS #: 181.00 Revision Date: September 25, 2013 J Use the Flinn Suggested Chemi­cal Storage SECTION 7 — HANDLING AND STORAGE Pattern to prevent accidents and improve safety. Flinn Suggested Chemical Storage Pattern: Organic #2. Store with alcohols, glycols, amines, and amides. Special storage and usage tips are also included. TM Store in a dedicated flammables cabinet. If a flammables cabinet is not available, store in Flinn Saf-Stor can. J Keep container tightly closed (P233). Keep cool (P235). Use only in a well-ventilated area or in a hood (P271). K Wear personal protective equipment such as SECTION 8 — EXPOSURE CONTROLS, PERSONAL PROTECTION goggles, gloves, and an apron. See page 1146– Wear protective gloves, protective clothing and eye protection (P280). Wash thoroughly after handling (P264). Use ventilation to 1147 for an explanation of exposure guidelines. keep airborne concentrations below exposure limits. Exposure guidelines: PEL 100 ppm (OSHA) TLV 20 ppm (ACGIH) K L Clear, concise, and useful physical and SECTION 9 — PHYSICAL AND CHEMICAL PROPERTIES chemical properties help you learn more about Clear colorless liquid. Wine-like odor. Boiling point: 117.7 C o the chemicals you use. The first part describes o Soluble: Water (20%). Miscible with alcohol and ether. Melting point: -89 C the material’s appearance. If it doesn’t look like L Refractive index: 1.3988 this, STOP. Do not use it. It may be more or less Specific gravity: 0.81 hazardous. SECTION 10 — STABILITY AND REACTIVITY Avoid contact with aluminum, chromium trioxide, and oxidizing materials. M Describes the conditions or reactions to be Substance may develop explosive hydroperoxides. M avoided. Also provides some indication about Shelf life: Fair, substance may oxidize. See Section 7 for further information. anticipated shelf life. SECTION 11 — TOXICOLOGICAL INFORMATION Acute effects: Absorbed through skin. Eye, skin, respiratory tract ORL-RAT LD50: 790 mg/kg N More detail on how the material may injure irritation. Dizziness. CNS depression. IHL-RAT LC50: 8000 ppm/4H Chronic effects: N.A. N SKN-RBT LD50: 3400 mg/kg O you. Acute (short exposure) and chronic (long- Target organs: Eyes, skin, respiratory system, central nervous term) effects are listed along with their target system. organs. N.A. = Not available, not all health aspects of this substance have been fully investigated. SECTION 12 — ECOLOGICAL INFORMATION O Oral (ORL), inhalation (IHL), and skin Data not yet available. P absorption (SKN) toxicity data on test animals is SECTION 13 — DISPOSAL CONSIDERATIONS included. For more information on LD50, see pages Please review all federal, state and local regulations that may apply before proceeding. 1148–1149. Flinn Suggested Disposal Method #18b is one option. Q Other useful information. SECTION 14 — TRANSPORT INFORMATION Shipping name: Butanols. Hazard class: 3, Flammable Liquid. UN number: UN1120. Sections 12–16. N/A = Not applicable R P Ecological impact if large amounts (e.g., tank SECTION 15 — REGULATORY INFORMATION TSCA-listed, EINECS-listed (200-751-6), RCRA code U031. S car) of the chemical spill near a river or lake. SECTION 16 — OTHER INFORMATION This Safety Data Sheet (SDS) is for guidance and is based upon information and tests believed to be reliable. Flinn Scientific, Inc. makes no guarantee of the accuracy or completeness of the data and shall not be liable for any damages relating thereto. The data is offered solely for your consideration, investigation, and verification. The Q Suggested disposal methods for laboratory data should not be confused with local, state, federal or insurance mandates, regulations, or requirements and CONSTITUTE NO WARRANTY. Any use of this data and information must be determined by the science instructor to be in accordance with applicable local, state or federal laws and regulations. The conditions or methods of quantities of chemicals. See pages 1188–1216 for handling, storage, use and disposal of the product(s) described are beyond the control of Flinn Scientific, Inc. and may be beyond our knowledge. FOR THIS AND OTHER REASONS, WE DO NOT ASSUME RESPONSIBILITY AND EXPRESSLY DISCLAIM LIABILITY FOR LOSS, DAMAGE OR EXPENSE ARISING OUT OF OR IN ANY Flinn Suggested Disposal Methods. WAY CONNECTED WITH THE HANDLING, STORAGE, USE OR DISPOSAL OF THIS PRODUCT(S). T Consult your copy of the Flinn Science Catalog/Reference Manual for additional information about laboratory chemicals. R Department of Transpor­tation shipping © 2013 Flinn Scientific, Inc. All Rights Reserved. PAGE 2 OF 2 information is included for your school district, emergency responders, and transport/shipping departments. S Regulatory information used by regulatory T Flinn Scientific has an ongoing program to compliance personnel. update its SDS. As professional chemists, we try our best to provide science teachers with the most accurate and useful safety information. Call Flinn if you have any questions. We can help! 7  Globally Harmonized System Pictograms Health Hazard Exclamation Mark Flame Carcinogen Irritant (skin and eye) Flammables Mutagenicity Skin Sensitizer Pyrophorics Reproductive Toxicity Acute Toxicity Self-Heating Respiratory Sensitizer Narcotic Effects Emits Flammable Gas Target Organ Toxicity Respiratory Tract Irritant Self-Reactives Aspiration Toxicity Hazardous to Ozone Organic Peroxides Layer (non-mandatory) Exploding Bomb Corrosion Environment Explosives Skin Corrosion/Burns (non-mandatory) Self-Reactives Eye Damage Aquatic Toxicity Organic Peroxides Corrosive to Metals Gas Cylinder Flame Over Circle Skull and Crossbones Gases Under Pressure Oxidizers Acute Toxicity (fatal or toxic) 8  Sample Label (Examples have been abbreviated) Product Identifier Product Name: _____________________ Acetone Chemical Name:____________________ Dimethylketone Supplier Identification Company Name:____________________ Street Address: _____________________ City :_______________ State:________ Signal Word Postal Code:___________ Country:_______ Danger Emergency Phone Number:_____________ Precautionary Statements Hazard Statement Protect against physical damage Highly flammable. Irritating to the eyes. Store in a cool, dry, well-ventilated location Vapors may cause drowsiness and dizziness. In Case of Fire: Use dry chemical, alcohol foam or carbon dioxide. Water may be ineffective. Supplemental Information First Aid: Immediately flush skin with plenty of (Provided by the manufacturer) water for at least 15 minutes. 1. Product identifier tells how the hazardous chemical is identified. This can be the chemical name, code number, or batch number. 2. Signal word is used to indicate the level of severity of hazard. “Danger” is used for the more severe hazards and “Warning” is used for the less severe hazards. 3. Pictograms are intended to convey specific information about the hazards of a chemical. They must be in the shape of a red outlined diamond with a black hazard symbol on a white background that is clearly visible. 4. Hazard statements describe the nature of the chemical hazard. 5. Precautionary statements describe measures that should be taken to minimize or prevent adverse effects from a hazardous chemical or improper storage or handling. 6. Supplemental information is additional information regarding the hazardous chemical and precautions for safe handling. osha.oregon.gov 440-4988-E (5/18/COM) 9  Properties and Changes of Matter I. Properties of Matter a. Intensive v. Extensive Properties i. Extensive – ii. Intensive – Examples: b. Physical v. Chemical Properties i. Physical - ii. Chemical - Examples: II. Phases of Matter Solid Liquid Gas 10 III. Changes of Matter a. Physical v. Chemical Changes i. Physical - ii. Chemical - iii. General Signs of a Chemical Change: Note – not all of these mean it’s a chemical change every time. It’s just an indicator for us to look closer! Examples: IV. Law of Conservation of Mass 11  Metals, Nonmetals and Metalloids One of the most iconic parts of chemistry is the periodic table, which we will use a lot this year. The table of elements is organized in a way that aligns with a lot of patterns of physical and chemical properties. Let’s consider our first pattern - the elements of the periodic table can be divided into three main categories of metals, nonmetals, and metalloids. Properties of Metals Properties of Nonmetals Properties of Metalloids How can we use these properties, along with other physical and chemical properties, to identify an unknown element? 12  Measurement & Significant Figures I. Key Terms When scientists collect quantitative data for their experiments, they use specific terms to describe and evaluate their data sets: Accuracy – how close a data point is to the accepted value Precision – how close data points are to each other Reliability – consistently using the same equipment and chemicals among experimental groups and repeated trials So a scientist could say their data is precise, but not accurate. Or reliable, but not precise. Let’s look at some examples… Examples: Assess the accuracy and precision of each target. What information would you need to be able to assess the reliability of this data? IV. Percent Error Indicates accuracy of a measurement % Error = experimental – true x 100 true Practice: A student estimated the mass of an object to be 250 g, but upon carefully measuring it, found the actual mass to be 240 g. What is the percent error? Joe measured the volume of an object five times and got results of: 34.5 mL, 34.9 mL, 34.2 mL, 33.4 mL, and 35.9 mL. The actual volume of the object was 34.1 mL. What is the percent error of his average result? 13  A student’s calculation was found to have a 15.6% error, and the actual value was determined to be 25.7 mL. What are the two possible values for the student’s experimental measurement? II. Using Measurement Tools When scientists measure, the instrument they use determines how many numbers they can record for their measurement. Exactness – Knowing that in any measurement, the last significant digit is considered an estimate Some Advice from Ms. Owens, Chemist: Take your measurement one decimal place past what the lines give you on the instrument. That’s your estimated digit! What should we record for the end measurement of the screw? II. Tools We Use Ruler – Measures length in centimeters or millimeters – NOT INCHES Graduated Cylinder – Measures volume in milliliters We never use beakers or flasks to measure volume. They are not calibrated for that, and graduated cylinders have more lines (or gradations). Thermometer – Measures temperature in Celsius or Kelvin – NOT FAHRENHEIT Balance – Measures mass in grams 14 IV. What is Mass? Usually, we expect to be given the WEIGHT of items, like when we step on a bathroom scale. However, in chemistry we use the MASS of items. MASS – measurement of the amount of matter WEIGHT – measurement of the amount of matter PLUS the gravitational pull on that matter Gravity is different at different elevations, so we use mass so that scientists all over the world can understand our data. V. Significant Figures We need to know how many significant figures are in a given measurement so that we can tell how precise it is. The more significant figures, the more precise! If you have a lot of significant figures, it means that you used a measuring instrument that has a very small scale (counting by 0.1 instead of 5, for example). A volume of 100.0 mL from a graduated cylinder is a lot more precise than 50 mL from a beaker, and it has the “sig figs” to prove it! A. Nonzero Integers Nonzero integers are numbers that are not zero! Nonzero integers are ALWAYS significant. They are NEVER placeholders. For example, in the number 1.36, there are three significant digits because all the numbers are nonzero integers. How many significant digits are there in the number 73,452? B. Zeros There are three types of zeros: Leading Zeros Captive (Sandwich) Zeros Trailing Zeros Each type follows different rules for determining significance. Leading Zeros Leading zeros are zeros that come before ANY and ALL of the nonzero digits. Leading zeros are NEVER significant. For example, the number 0.0017 (1.7x10-3) has only TWO significant figures because it has three leading zeros. How many significant figures does the number 0.0829 have? Captive (Sandwich) Zeros Captive zeros are zeros that are BETWEEN two nonzero digits. Captive zeros are ALWAYS significant. For example, the number 1007 (1.007x103) has FOUR significant figures. How many significant figures does the number 0.080029 have? 15  Trailing Zeros Trailing zeros are zeros that are at the END of the number (on the right side). Trailing zeros are only significant if the number has a DECIMAL ANYWHERE. For example, the number 400 (4x102) has only ONE significant figure, but the number 400. (4.00x102) has THREE because of the decimal point. How many significant figures does the number 4070.00 have? VI. Math with Significant Figures When you add, subtract, multiply or divide two numbers, the answer has a set number of significant figures based on the problem. A. Multiplication & Division When we MULTIPLY or DIVIDE, your answer has the same number of “sig figs” as the number with the fewest sig figs from the original problem. For example: 34.91 x 0.0053 = 0.185023 rounds to… B. Rounding Refresher - If you need to round your answer (get rid of some numbers) to fit a certain number of significant digits… Look at the digit to the RIGHT of where you want your number to end. If it is LESS than 5, you keep the new end digit the same and drop the rest. If it is EQUAL TO or GREATER than 5, you “round up” and increase the new end digit by 1, then drop the rest. Examples: Round 4.32 to two significant figures: Round 2.7636 to two significant figures: C. Addition & Subtraction When we ADD or SUBTRACT, your final answer has the least number of DECIMAL PLACES from the original problem. For example: 12.72 + 34.1 + 0.463 = 47.283 rounds to… D. Exact Number Exceptions Exact numbers are numbers that are determined by counting or are a part of a definition. Exact numbers have an infinite number of significant figures, so they can NEVER determine rounding of an answer. Examples: Counting: There are 27 students in this classroom. I have three pencils on my desk. Definitions: One foot is defined as 12 inches. One yard is defined as three feet. 16  Defined or Exact Calculated Infinite Significant Figures, Will Not Limit Limits Significant Figures Metric Conversions Metric to Nonmetric (ex: 10 dg = 1 g) (ex: 1 gallon = 3.79 L) Minutes, Hours, Seconds 1 min = 60 s Other values that have been measured 1 hr = 60 min (ex: The diameter of a quarter = 2.3 cm) 24 hr = 1 day 1 inch = 2.54 cm Counted Numbers (ex: 18 loaves of bread) Note: When an equivalency like 1 gallon = 3.79 L is given, it’s the 3.79 that limits the significant figures. The 1 is not measured. It’s like saying 3.79 L/gallon, and the 1 is understood (like x in algebraic expressions). VII. Scientific Notation Used to express very large or very small numbers Significant figures in scientific notation should match those in standard notation In correct scientific notation, all digits of “M” end up significant! M x 10n VIII. Percent Error Calculations When comparing measured or calculated values to theoretical true values, scientists often report this as a percent error relative to the theoretical value. The error in an experimental value should be attributable to specific things in the lab, such as the precision of equipment used, assumptions made in the experimental design, etc. 𝐸𝑥𝑝𝑒𝑟𝑖𝑚𝑒𝑛𝑡𝑎𝑙−𝑇ℎ𝑒𝑜𝑟𝑒𝑡𝑖𝑐𝑎𝑙 Percent Error = 𝑇ℎ𝑒𝑜𝑟𝑒𝑡𝑖𝑐𝑎𝑙 ×100 17  Name: _____________________________ Date: _______________ Period: ________ Significant Digits Practice Indicate how many significant digits are in the following measurements: a) 5.68 g __________ e) 1.90 cm __________ b) 2.09 mL __________ f) 1.350 cL __________ c) 1.099 km __________ g) 2,530 mm __________ d).09 dg __________ Round each number to 3 significant digits: h) 19095 ______________ k) 0.59820 ______________ i) 17.249 ______________ l) 6988042 ______________ j).032991 ______________ m) 468.302 ______________ Complete the following calculations and write the answer from your calculator on the first line. On the second line, write your answer in the correct number of significant digits. n) 3.14g x 5.6g= ____________________ _____________________ o) 300mL x 10.6mL= ____________________ _____________________ p) 0.059cm x 6.95cm= ____________________ _____________________ q) 80g /0.675mL= ____________________ _____________________ r) 0.003km/106km= ____________________ _____________________ s) 4.60g + 3g = ____________________ _____________________ t) 0.008dm + 0.05dm = ____________________ _____________________ u) 22.4420cL + 56.981cL = ____________________ _____________________ v) 200ms - 87.3ms = ____________________ _____________________ w) 67.5kL - 0.009kL = ____________________ _____________________ 18  Conversions & Dimensional Analysis I. SI Units Sometimes, we need different units from the ones that we are given so we have to convert from one to another. In chemistry, we use SI (Système Internationale) base and derived units that everyone in the world also uses. Base Units: Distance/Length → Time → Mass → Derived Units: Volume → Density → II. Metric Conversions These are definitions so do not limit significant figures in conversions. Prefix Symbol Multiplier giga G 109 1,000,000,000 mega M 106 1,000,000 kilo k 103 1,000 None (Base) (none) 1 1 deci d 10-1 0.1 centi c 10-2 0.01 milli m 10-3 0.001 micro µ 10-6 0.000001 nano n 10-9 0.000000001 Length Example: There are 1000 millimeters in a meter. There are 100 centimeters in a meter. There are 10 decimeters in a meter. There are 1000 meters in a kilometer. 19  III. Common Metric to Nonmetric Conversion Many are not definitions, with a few exceptions (noted with a *), and so do limit significant figures in conversion calculations. 1 yard = 0.9144 meters Distance 1 foot = 0.3048 meters 1 inch = 2.54 centimeters* 60 seconds= 1 minute* Time 60 minutes= 1 hour* 1440 minutes = 24 hours = 1day* Mass 1 kilogram = 2.2 pounds Volume 1 cm3 = 1 mL* IV. The Mole – The SI Unit of Chemistry a. This is the SI base unit most commonly associated with chemistry, because we use it to easily count or package atoms, molecules, ions, etc. b. One mole (mol) contains exactly 6.02214076 × 1023 elementary entities. It is called Avogadro’s number (even though he didn’t calculate it!) In calculations, often rounded to 1 mol = 6.022x1023 items A VERY large amount! c. You can have a mole of anything; it’s just a number V. Dimensional Analysis (AKA the factor-label method) Step 1: Draw your set-up. Step 2: Put in your given amount from the question. Step 3: Put in the conversions that you know relative to the base unit. Matching units are diagonal, so they can cancel out. Step 4: Continue adding conversion factors until you get the unit asked for in the question. Step 5: Cross out the units that cancel, to make sure you’re getting the correct unit in the end. Step 6: Do the math! Multiply by things in the numerator, and divide by the denominators. And make sure to round your answer to the correct number of significant figures. Example: How many milliliters are in 12.4 centiliters? 20 Practice: How many centimeters are in 6.9 meters? How many milliliters are in 2.4 deciliters? How many kiloseconds are in 5.99 milliseconds? How many centimeters are in 4.00 miles? (1609 meters = 1 mile) How many atoms are in 3.25 moles of silicon? What is the mass of 15.0 cm3 of aluminum? The density of aluminum is 2.70 g/cm3. What is the volume of 25 g of ethyl alcohol (density = 0.79 g/mL)? The diameter of metal wire is often referred to by its American wire gauge number. A 16-gauge wire has a diameter of 0.05082 in. What length of wire, in meters, is there in a 1.00-lb. spool of 16-gauge copper wire? The density of copper is 8.92 g/cm3. 21  Dimensional Analysis Practice 1 US fl oz = 29.57 mL 1 quart = 946.4 mL 1 kg = 2.205 lbs 1 quart = 4 cups* 1 metric ton = 1000 kg* 1 mile = 1609 m 1 mass oz = 28.35 g 1 yd = 3 ft* 1 gallon = 4 quarts* 1 yd = 0.9144 m 1 inch = 2.54 cm* *defined or exact value 1. Convert 124.0 days into seconds. 2. Convert 9.75 x 107 fluid ounces of water (density = 0.99998 g/mL) into metric tons. 3. Convert 3.87 x10-8 km into cm. 4. Convert 67 U.S. quarts into kL. 5. Convert 6.5 pounds into cups if the density of the liquid is 2.03 g/L. 6. Convert 3.409 miles per hour into km per minute. 7. Convert 56.2 m3 into yd3. 22 8. What is the density of a mystery liquid in g per mL if 65.0 fluid ounces weighs 202 mass ounces? 9. A piece of gold leaf (density 19.3 g/cm3 ) weighs 1.93 mg. What is the volume in mm3 ? 10. What is a better deal, a one gallon gasoline for $2.89 or one liter of gasoline for $0.75? Support your answer using calculations. 11. A car travels at a rate of 65 miles per hour. If the car gets 33.5 miles to the gallon, how many hours can a car travel on 25.0 pounds of fuel? (density of fuel is 6.50 pounds/gallon) 12. The recommended dose of a medication is 5 mg/kg body weight. You have a patient whose weight is 125 pounds. The pharmacy offers three different oils containing 500 mg, 250 mg, and 100 mg of medication. Which pill should you give your patient? 13. The bromine content of the ocean is about 65 grams of bromine per million grams of sea water. How many cubic meters of ocean must be processed to recover 1.0 pounds of bromine if the density of sea water is 1.0 x 103 kg/m3 ? 14. An average man requires about 2.00 mg of fiboflavin (vitamin B2) per day. Cheese contains 5.5µg of riboflavin per gram of cheese. How many pounds of cheese would a man have to eat per day if this is his only source of riboflavin? 23 15. Alan is going to the Boy Scouts Jamboree in DC next summer and he has been asked to bring the smores supply for all the boys going from the district in Oregon. Each giant chocolate bar makes 16 smores. Each boy will be limited to exactly 3 smores. The problem is that he has to buy the chocolate once he gets to DC because there will be too many of them and they may melt in the summer heat. On average, the stores only carry 25 of these giant chocolate bars in stock. How many stores will he have to visit if there are 2,225 boys? 16. In the yearly fundraiser at school, kids can earn a hamburger phone if they raise at least $250 in donations. Aaron was able to get all of his family and family friends to pledge enough money that he will earn $35 for each mile he runs. The problem is he runs very slowly, 88 inches per second. How many hours will it take him to run just long enough to earn the hamburger phone? 24 Classification of Matter 25 What Am I? Classify each as Element (E), Compound (C), Heterogeneous Mixture (HM), or Homogeneous Mixture/Solution (S). Cherry Jell-o with Bananas Aluminum, Al Plain Cherry Jell-o Magnesium, Mg Rocky Road Ice Cream Acetylene, C2H2 Plain Vanilla Ice Cream Tap Water Chicken Noodle Soup Soil Tomato Soup Pure Water , H2O Concrete Chromium, Cr Sugar Water Chex Mix Iron Filings, Fe Salt Water Chalk, CaCO3 Benzene, C6H6 Orange Juice Muddy Water Ocean Water Brass (An Alloy of Copper and Zinc) Air in Balloon Baking Soda, NaHCO3 Laws of Definite and Multiple Proportions Law of Definite Proportions: Law of Multiple Proportions: Percent by Mass: 26  Naming Simple Binary Compounds I. Types of Compounds a. There are two major classifications of compounds as pure substances with definite proportions of elements - ones held together by ionic bonds, and ones with covalent bonds. b. We’ll get deeper into this as the year progresses to refine our understanding of the differences (and gray areas) of each, but for now, we can start with a broad definition: Ionic Compounds Covalent Compounds c. We distinguish these types of compounds with their naming. Let’s consider the simplest compounds we can have, where only two elements are involved, called binary compounds. NaCl CO2 What do you already know about their naming? What rules do we follow to name them? 27  Naming Molecular Compounds How are the chemical formula and name of a molecular compound related? Why? When you began chemistry class this year, you probably already knew that the chemical formula for car- bon dioxide was CO2. Today you will find out why CO2 is named that way. Naming chemical compounds correctly is of paramount importance. The slight difference between the names carbon monoxide (CO, a poisonous, deadly gas) and carbon dioxide (CO2, a greenhouse gas that we exhale when we breathe out) can be the difference between life and death! In this activity you will learn the naming system for molecu- lar compounds. Model 1 – Molecular Compounds Molecular Number of Atoms Number of Atoms Name of Compound Formula of First Element of Second Element ClF Chlorine monofluoride ClF5 1 5 Chlorine pentafluoride CO Carbon monoxide CO2 Carbon dioxide Cl2O Dichlorine monoxide PCl5 Phosphorus pentachlroride N2O5 Dinitrogen pentoxide 1. Fill in the table to indicate the number of atoms of each type in the molecular formula. 2. Examine the molecular formulas given in Model 1 for various molecular compounds. a. How many different elements are present in each compound shown? b. Do the compounds combine metals with metals, metals with nonmetals, or nonmetals with nonmetals? c. Based on your answer to b, what type of bonding must be involved in molecular compounds? 3. Find all of the compounds in Model 1 that have chlorine and fluorine in them. Explain why the name “chlorine fluoride” is not sufficient to identify a specific compound. 4. Assuming that the name of the compound gives a clue to its molecular formula, predict how many atoms each of these prefixes indicates, and provide two examples. mono- di- penta- Naming Molecular Compounds 1 28 Model 2 – Prefixes and Suffixes Prefix Numerical Value Molecular Formula Name of Compound mono- BCl3 Boron trichloride di- SF6 Sulfur hexafluoride tri- IF7 Iodine heptafluoride tetra- NI3 Nitrogen triiodide penta- N2O4 Dinitrogen tetroxide hexa- Cl2O Dichlorine monoxide hepta- P4O10 Tetraphosphorus decoxide octa- B5H9 Pentaboron nonahydride nona- Br3O8 Tribromine octoxide deca- ClF Chlorine monofluoride 5. Examine the prefixes in Model 2. Fill in the numerical value that corresponds to each prefix. 6. What suffix (ending) do all the compound names in Model 2 have in common? 7. Carefully examine the names of the compounds in Model 2. When is a prefix NOT used in front of the name of an element? 8. Consider the compound NO. a. Which element, nitrogen or oxygen, would require a prefix in the molecule name? Explain your answer. b. Name the molecule NO. 9. Find two compounds in Model 2 that contain a subscript of “4” in their molecular formula. a. List the formulas and names for the two compounds. b. What is different about the spelling of the prefix meaning “four” in these two names? 2 POGIL™ Activities for High School Chemistry 29  10. Find two compounds in Model 2 that contain the prefix “mono-” in their names. a. List the formulas and names for the two compounds. b. What is different about the spelling of the prefix meaning “one” in these two names? 11. Identify any remaining names of compounds in Model 2 where the prefixes that do not exactly match the spelling shown in the prefix table. 12. Use your answers to Questions 9–11 to write a guideline for how and when to modify a prefix name for a molecular compound. Come to a consensus within your group. 13. Would the guideline you wrote for Question 12 give you the correct name for NI3 as it is given in Model 2? If not, modify your guideline to include this example. 14. All of the compounds listed in Model 2 are binary molecular compounds. Compounds such as CH3OH or PF2Cl3 are not binary, and compounds such as NaCl or CaCl2 are not molecular. Propose a definition for “binary molecular compounds.” 15. Collaborate with your group members to write a list of rules for recognizing and naming binary molecular compounds from their chemical formulas. Naming Molecular Compounds 3 30  16. For each of the following compounds, indicate whether or not your naming rules from Question 15 will apply. If not, explain why the naming rules do not apply. FeI3 ICl5 HBrO4 17. Using the rules your group developed in Question 15, name each of the following molecular compounds. Molecular Formula Molecule Name PBr3 SCl4 N2F2 SO3 BrF 18. Write molecular formulas for the following compounds. Molecular Formula Molecule Name Disulfur decafluoride Carbon tetrachloride Oxygen difluoride Dinitrogen trioxide Tetraphosphorus heptasulfide 4 POGIL™ Activities for High School Chemistry 31 Extension Questions 19. This activity focused on molecular (covalent) compounds, while an earlier activity addressed ionic compounds. Notice that the formulas for both types of compounds can look very similar, even though their names are quite different: Chemical Formula Type of Compound/Bonding Compound Name MgF2 Ionic Magnesium fluoride CuF2 Ionic Copper(II) fluoride SF2 Molecular (covalent) Sulfur difluoride NaBr Ionic Sodium bromide AuBr Ionic Gold(I) bromide IBr Molecular (covalent) Iodine monobromide Identify two differences between the names or formulas for ionic compounds versus those for binary molecular compounds. Also identify two similarities. Names and Formulas Names and Formula of of Ionic Compounds Molecular (Covalent) Compounds Differences Similarities 20. Use complete sentences to explain why AlCl3 is called “aluminum chloride” (no prefix required), but BCl3 is called “boron trichloride.” Naming Molecular Compounds 5 32  Separating a Mixture a. Decanting - Used when solid or residue has settled to bottom and can pour off the top liquid Ex: sand and water b. Evaporation - Used when one substance will physically change its state of matter when heated. Ex: salt water c. Filtration - Used when have solids of different particle size. Solid, or residue, is trapped by porous barrier, such as filter paper, and the liquid, or filtrate, is collected in beaker or flask. Ex: Straining cooked pasta water or making coffee d. Chromatography - Used when have two or more liquids with different absorption rates. Ex: pigments e. Distillation – used to separate two liquids with different boiling points. Ex: Distilling alcohol, or crude oil into gasoline f. Centrifugation – spins mixtures to separate particles by density Ex: blood 33  Percent Yield & Percent Error Practice with Separations 𝐸𝑥𝑝𝑒𝑟𝑖𝑚𝑒𝑛𝑡𝑎𝑙 𝐸𝑥𝑝𝑒𝑟𝑖𝑚𝑒𝑛𝑡𝑎𝑙−𝑇ℎ𝑒𝑜𝑟𝑒𝑡𝑖𝑐𝑎𝑙 Percent Yield = 𝑇ℎ𝑒𝑜𝑟𝑒𝑡𝑖𝑐𝑎𝑙 ×100 Percent Error = 𝑇ℎ𝑒𝑜𝑟𝑒𝑡𝑖𝑐𝑎𝑙 ×100 “Theoretical” value means the true, expected, or accepted value. 1. You and your lab partner decide to do a distillation of an ethanol and water mixture. The boiling point of ethanol is 78.37°C, while water’s is 100.00°C. a. Which one will vaporize and condense as a fraction first? b. The original mixture sample was 31.42 g, while the collected ethanol was 22.60 g and the collected water was 6.48 g. Calculate the percent yield of the separation. c. Calculate the percent error of the separation. What could have happened during the lab to cause this error? 2. You and your lab partner decide that you want to use a centrifuge. You live on a farm, so you decide to milk a cow and put the dairy product into the centrifuge. As it separates, you get milk and cream. The Separation of Dairy Product by Centrifugation Volume (L) Dairy Product 26.4 Separated Cream 14.8 Separated Milk 10.3 a. What is the percent by volume of the mixture that is milk? b. What is the percent yield of the separation? c. What is the percent error? 34