Name KEY Period CRHS Academic Chemistry Unit 1 Matter and Change HOMEWORK Due Date Assignment On-Time (100) Late (70) 1.1 1.2 1.3 Warm Ups Notes, Homework, Exam Reviews and Their KEYS located on CRHS Academic Chemistry Website: https://cincochem.pbworks.com
Page 2 of 8 Warm-Up Unit 1 Homework #1 #6 #2 #7 #3 #8 #4 #9 #5 #10
HW 1.1 CLASSIFYING MATTER Unit 1 Homework Page 8 1. What is matter? Anything that has mass and takes up space 2. Name 3 properties of solids. Definite shape; definite volume; particles packed closely together 3. Name 3 properties of liquids. Variable shape; definite volume; particles are packed Loosely together 4. Name 3 properties of gases. Variable shape; variable volume; particles far apart Classify each of the following properties as either chemical or physical by putting a check in the appropriate column. 5. blue color X Physical Chemical 6. density X 7. flammability X 8. solubility X 9. reacts with acid to form H 2 X 10. combusts easily X 11. sour taste X 12. mass X 13. reacts with water to form a gas X 14. explodes when in contact with water X 15. hardness X 16. boiling point X 17. can neutralize a base X
Page 4 of 8 Unit 1 Homework Physical 18. length X Chemical 19. odor X 20. reacts with a base to form water X 21. Using the list above, name 2 intensive physical properties. blue color, density, flammability, solubility, sour taste, hardness, boiling point 22. Using the list above, name 2 extensive physical properties. Mass, length 23. For each sample below, determine if the contents represent an element (E), compound (C), homogeneous (HOM) or heterogeneous mixture (HET). Then a) Circle the substances that can be separated by physical means Phys b) Box the substances that can be separated by chemical means Chem c) Star the pure substances. * HET_ Iced Tea with table sugar (C 12H 22O 11) Phys E Aluminum metal (Al) * HET_ Table Salt (NaCl) and sand (SiO 2) Phys E Copper metal (Cu) * E Sulfur dust (S) * C Water (H 2O) *Chem HET Olive Oil and water Phys HOM_ Kool-aid and water Phys C Baking soda (NaHCO 3) *Chem E Iron metal (Fe) * HET Iron metal and sulfur dust (Fe and S) Phys E Carbon dust (C) * HOM Stainless steel (Fe, Cr, Ni, Mo, C, Mn) Chem C Copper (II) sulfate (CuSO 4) crystals *Phys HET A speckled rock Chem HOM Crude Oil (C 5H 12, C 8H 18, C 4H 10, C 20H 42, others) Phys
HW 1.2 DENSITY Unit 1 Homework Page 8 1. What is the density of an object with a mass of 45 grams and a volume of 5.0 ml? D = M V = 45 g 5.0 ml = 9.0 g ml CIRCLE ONE Will this object float or sink in water? ( FLOAT / SINK ). How do you know? Sink because density greater than 1 g/ml 2. What is the density of an object that has a mass of 5.0 grams and a volume of 72.3 ml? D = M V = 5.0 g 72.3 ml = 0.0691 g ml = 0.069 g ml 0.069 g/ml 3. What is the density of an object that has a volume of 232.0 m 3 and a mass of 273 kg? 1.18 kg/m 3 4. The density of mercury is 13.6 g/ml. How many milliliters are there in 300.0 grams of mercury? D = M V V x D = M V = M D 5. A solution of hydrochloric acid has a density of 1.12 g/ml. 300.0 g = 13.6 g = 22.06 ml = 22.1 ml ml 22.1 ml a) Calculate the mass of 250 ml of the solution. D = M V D x V = M 1.12 g ml x 250 ml = 280 g 280 g b) Calculate the volume occupied by 250 grams of the solution. D = M V x D = M V = M 250.0 g = V D 1.12 g = 223.2 ml = 220 ml ml 220 ml 6. The density of uranium is 18.9 g/ cm 3. What is the mass of 2.00 cm 3 of Uranium? 37.8 g 7. The density of uranium is 18.9 g/ cm 3. What is the volume of 27 grams of Uranium? 1.4 cm 3
Page 6 of 8 Unit 1 Homework HW 1.3 PHYSICAL vs. CHEMICAL CHANGE & CONSERVATION OF MASS 1. Classify each of the following as being a physical (P) or chemical (C) change: P Sodium hydroxide dissolves in water. C Hydrochloric acid reacts with potassium hydroxide to produce a salt, water, and heat. P A pellet of sodium is sliced in two. P Water is heated and changed to steam. C Potassium chlorate decomposes to potassium chloride and oxygen gas. C Iron rusts. P Evaporation P Ice melting P Sugar dissolves in water. C Wood rotting C Pancakes cooking on a griddle C Grass growing in a lawn P A tire is inflated with air. C Food is digested in the stomach. P Water is absorbed by a paper towel. C When placed in water, a sodium pellet catches on fire as H 2 gas is liberated and NaOH forms. C Milk sours 2. List the 4 indicators of a chemical change: 1) Heat Exchange 2) Color Change 3) Production of Gas 4) Formation of Precipitate 3. You are tutoring a 5 th grade science student. Write 4 original (not from your notes) sentences describing the difference between physical and chemical changes. Be sure to include examples.
Unit 1 Homework Page 8 4. State the law of conservation of mass in words: matter cannot be created or destroyed 5. State the formula for the law of conservation of mass: Mass Reactants = Mass Products Fill in the missing mass for # s 6 through 13 6. 17.0 g sodium + 129.2 g magnesium fluoride 47.4 g sodium fluoride + 98.8 g magnesium 7. 96.3 g sodium + 12.2 g magnesium fluoride 21.4 g sodium fluoride + 87.1 g magnesium 8. Na + Cl NaCl 30.5 g 41.84 g 72.34 g 9. 2Ca + O 2 2CaO _118.2 g 38.2 g 156.4 g 10. 2Na + MgF 2 2NaF + Mg 17.0 g 129.2 g 47.4 g _98.8_ g 11. 2Na + MgF 2 2NaF + Mg 96.3 g 12.2 g 21.4 g 87.1 g 12. 4Na + O 2 2Na 2O 52.1_g 15.8 g 67.9 g 13. 2Na + 2HCl H 2 + 2NaCl 41.8_g 31.2 g 47.1g 25.9 g 14. 40 g of calcium reacts with 71 g of chlorine to produce _111_ g of calcium chloride. 15. 78 g of potassium reacts with 16 g of oxygen to produce 94 g of potassium oxide. 16. In the following reaction: 2NaN 3 decomposes to form 2Na + 3N 2. If 500 grams of NaN 3 decomposes to form 323.20 grams of N 2. How much Na is produced? 176.8 or 177 g
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