Complete the blank labels in the diagram below. WKS 3.1 - Classifying Matter (2 pages) State whether each of the following is a homogeneous mixture, heterogeneous mixture, compound, or an element. Explain how you made your decision in each case. Element, Compound, Homogeneous Explanation supporting decision Mixture, or Heterogeneous Mixture 1. hydrogen 2. table salt 3. sugar water 4. carbon dioxide 5. ketchup 6. pure air (tricky!) 7. water 8. soil 9. 70% rubbing alcohol 10. iron 11. rocky road ice cream 90% of a worksheet must be completed to earn credit for that worksheet! Page 1 of 10
WKS 3.1 - Classifying Matter (continued) 12. How can one tell the difference between a colloid and suspension? 13. How can one tell the difference between a solution and a colloid? 14. What are some examples of physical separation? 15. For each type of mixture draw a picture representing the size and distribution of particles in a liquid. SOLUTION COLLOID SUSPENSION 16. Lupita states that blood is a heterogeneous mixture while Sven states that blood is a heterogeneous mixture. Who is correct in this argument? Design an experiment that would defend your argument. 17. Compare and contrast a mixture and a compound. How are they alike? How are they different? 18. A chemist heats some white crystals in a test tube. The crystals make a cracking sound, fall apart into smaller pieces, and give off a misty gas. A colorless liquid forms around the cooler top of the test tube. Tell whether you think the crystals are a compound or an element, and why. 90% of a worksheet must be completed to earn credit for that worksheet! Page 2 of 10
WKS 3.2 Chemical vs. Physical Properties (1 page) Classify the following properties as either chemical or physical (write out the whole word) and then justify your answer with an explanation. Physical or Explanation supporting your decision Chemical Property 1. Blue color 2. Density 3. Flammability 4. Solubility 5. Reacts with acid to form H 2 6. Supports combustion 7. Odor 8. Melting point 9. Reacts with water to form a gas 10. Luster 11. Boiling point 12. Can neutralize a base Physical properties can be further broken down into two types INTENSIVE & EXTENSIVE. Be sure to write out the whole word. It will be VERY helpful to you in the future to know this because IF a property is INTENSIVE, then we can safely assume any convenient amount we want! 13. Mass 14. Number of atoms 15. Color 16. Odor 17. Melting point 18. Density 19. Malleability 20. Volume 21. Length 22. Electrical Conductivity Intensive or Extensive Explanation supporting your decision 90% of a worksheet must be completed to earn credit for that worksheet! Page 3 of 10
WKS 3.3 Chemical vs. Physical Changes (1 page) In a physical change, the original substance still exists. It has only changed in form. In a chemical change, a new substance is produced. Classify the following as being a physical or chemical change. If it is chemical, state what evidence(s) of a chemical change would be seen in the example. 1. Sodium hydroxide dissolves in water. 2. Hydrochloric acid reacts with potassium hydroxide to produce a salt, water and heat. 3. A pellet of sodium is sliced in two. 4. Water is heated and changed to steam. 5. Potassium chlorate decomposes to potassium chloride and oxygen gas. 6. Iron rusts. 7. When placed in H 2 O, a sodium pellet catches on fire as hydrogen gas is liberated and sodium hydroxide forms. 8. Evaporation. 9. Ice melting. 10. Sugar dissolves in water. 11. Wood rotting. 12. A tire is inflated with air. 13. Food is digested by hydrochloric acid in the stomach. 14. Water is absorbed by a paper towel. 15. Breaking a piece of glass with a hammer. 16. Milk is left outside of a refrigerator for seven months and spoils. 17. Dew forms on trees leaves from condensation. 18. Water is purified by a process of filtration. 19. Leaves changing color in the autumn. 20. A student fries an egg for a yummy breakfast. 21. Fermenting of cider. 22. Burning wood. 23. Silver tarnishing. 90% of a worksheet must be completed to earn credit for that worksheet! Page 4 of 10
WKS 3.4 States of Matter (2 pages) 1. What are the differences between intramolecular bonding and intermolecular forces? 2. For each of the following, indicate if it represents a solid, liquid, or gas. Definite volume, definite shape Molecules organized in set pattern Molecules far apart Least dense Strongest intermolecular interactions Diffuses an immeasurable amount Easily compressed Definite volume, no definite shape Incompressible Diffuse easily but slowly Most dense Molecules close, but have free motion No intermolecular interactions No definite shape, no definite volume Vibrations only of molecules Diffuse easily and quickly 3. Match the pictures with the following descriptions. SOLID LIQUID GAS Diatomic Gas Liquid Solid Liquid with Diatomic Gas 4. Compare and contrast the motion of particles of solids, liquids, and gases. 5. Gases and liquid are both fluids; they can flow. What is different about the intermolecular forces of attraction between the phases that allows fluids and gases to flow, but prevent solids from flowing? 90% of a worksheet must be completed to earn credit for that worksheet! Page 5 of 10
WKS 3.4 States of Matter (continued) 6. For each phase transition listed in the center column, draw and arrow from the beginning phase, through the transition, to the ending phase. The first is done for you. Gas Sublime Gas Freeze Liquid Boil Liquid Condense Solid Deposition Solid Melt 7. For each of the six phase changes, which ones are considered endothermic (taking in heat)? Which ones are considered exothermic (releasing heat)? 8. Why do ice cubes shrink if left in the freezer for a long time? Why do moth balls disappear? (Hint: the same thing is happening in both cases.) 9. Your breath contains water vapor. Why does it look like smoke in cold weather? Explain this using phase changes. 10. Energy is added to a solid substance at a constant rate. The temperature of the substance rises for a while, but a point is reached at which the temperature does not rise. At this point, what is happening to the substance? Describe what is happening to the energy being supplied to the solid during this time. 11. Distinguish between evaporation and vaporization. 90% of a worksheet must be completed to earn credit for that worksheet! Page 6 of 10
WKS 3.5 Heating/Cooling Curves (1 page) The graph below shows a pure substance which is heated by a constant source of heat supplying 2000.0 joules per minute. Identify the area described in the questions below and complete the necessary calculations. UV = 0.36 min, VW = 3.6 min, WX = 3.6 min, XY = 19.4 min, YZ = 0.6 min (2000.0 joules applied per minute) 1. Being warmed as a solid 2. Being warmed as a liquid 3. Being warmed as a gas 4. Changing from a solid to a liquid 5. Changing from a liquid to a gas 6. States present from V to W? 7. Sates present from X to Y? 8. What is its boiling temperature? 9. What is its melting temperature? 10. How many joules were needed to change the liquid to a gas? 11. Where on the curve do the molecules have the highest kinetic energy? 12. What happened to the temperature during a phase change? WHY? =============================================================================== Identify the following phase transition and write it on the first line. On the second line, indicate whether energy belongs on the product side or the reactant side of the equation. Phase transition Energy side 13., CH 3 CH 2 OH (l) CH 3 CH 2 OH (g) 14., Al (l) Al (s) 15., I 2 (s) I 2 (g) 16., W (s) W (l) 17., N 2 (g) N 2 (l) 90% of a worksheet must be completed to earn credit for that worksheet! Page 7 of 10
Pressure (atm) Pre-AP Chemistry Unit 3 HW Packet WKS 3.6 Phase Diagram (1 page) Answer the following questions regarding the phase diagram of ammonia. 111.5 1.0 0.05997 195.42 239.8 405.38 Temperature (K) 1. Label the solid, liquid, and gas phases on the above chart. 2. Use arrows to label and indicate the following phase changes: a. Melting b. Freezing c. Vaporization d. Condensation e. Sublimation f. Deposition 3. What is the triple point of ammonia? 4. What phase(s) are present at the triple point? 5. If ammonia is compressed from 0.005 atm to 0.995 atm at a constant temperature of 230 K, what phase change is observed? 6. If ammonia heated from 25 K to 195.42 K at a constant pressure of 0.025 atm, what phase change is observed? 7. If a substance s pressure and temperature are found to fall on the line, we would say that substance is in a phase equilibrium. What is the definition of equilibrium? 90% of a worksheet must be completed to earn credit for that worksheet! Page 8 of 10
WKS 3.7 Review Part One (1 page) 1. Identify each of the following as intensive or extensive. a. melting point c. density b. mass d. length 2. "Properties are not affected by changes in temperature and pressure." Is this statement true or false? EXPLAIN! 3. Classify each of the following as either solid, liquid, or gas at room temperature. a. milk d. helium b. air e. diamond c. candle wax f. copper 4. Classify each of the following as a physical property (PP) or a chemical property (CP). a. aluminum has a silvery color d. water boils at 100 C b. gold has a density of 19.3 g/cm 3 e. sodium ignites when dropped in water c. silver tarnishes f. mercury is a liquid at room temperature 5. Classify each of the following as a physical change (PC) or a chemical change (CC) a. breaking a pencil in two d. burning wood b. water freezing and forming ice e. leaves turning color in the fall c. frying an egg f. water evaporating 6. Is a change in phase a physical change or chemical change? EXPLAIN! 7. List four indicators that a chemical change has probably taken place. a. c. b. d. 8. Describe the difference between a chemical change and a physical change. 9. "A mixture is a chemical bonding of two or more substances in any proportion". Is this statement true or false? EXPLAIN! 90% of a worksheet must be completed to earn credit for that worksheet! Page 9 of 10
WKS 3.8 Review Part Two (1 page) 1. Describe how a homogeneous mixture differs from a heterogeneous mixture. 2. Identify each of the following as an example of a physical property (PP) or a chemical property(cp). a. Silver tarnishes when it comes in contact with hydrogen sulfide in the air b. A sheet of copper can be pounded into a bowl. c. Barium melts at 725 C. d. Helium does not react with any other element. e. A bar of lead is more easily bent than is a bar of aluminum of the same size. f. Potassium metal is kept submerged in oil to prevent contact with oxygen or water. g. Diamond dust can be used to cut or grind most other materials. 3. Identify each of the following as a property of a solid, liquid, or gas. Some answers will include more than one state of matter. a. flows and takes the shape of its container b. compressible c. made of particles held in a specific arrangement d. has a definite volume e. always occupies the entire space of its container f. has a definite volume but flows 4. Identify each of the following as an example of a element (ELE), a compound (COMP), homogeneous mixture (HOM) or a heterogeneous mixture (HEM). a. 70% isopropyl rubbing alcohol h. salt water b. aluminum foil i. concrete c. gasoline j. bread d. sucrose (table sugar) k. a pile of rusty filings e. a diamond l. hydrogen in a balloon f. fruit salad m. air in a balloon g. carbon dioxide n. dirt 5. Can two different samples of the same substance have different physical properties? Can they have different chemical properties? Explain your answers to both questions. 90% of a worksheet must be completed to earn credit for that worksheet! Page 10 of 10