Name Sec: 11am 1:30pm PH-218 Exam II Sample Exam. PART I: Short Answer. 1. (6 pts) Complete the following statements or answer the question.

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1 PART I: Short Answer Name Sec: 11am 1:30pm PH-218 Exam II Sample Exam 1. (6 pts) Complete the following statements or answer the question. a. In the formula CaH 2 (NH 3 ) 2 (SO 4 ) 2 there are total atoms. This molecule also has a total of subunits. b. Name an element that is a liquid at room temperature. 2. (18 pts) True/False. Write true or false in front of each statement. a. The reaction of baking soda and vinegar to produce carbon dioxide gas is an example of a precipitation reaction. b. When water is heated, bubbles are formed in the water. This is evidence of a chemical reaction occurring. c. PbS + Mg MgS + Pb is an example of a double replacement reaction. d. Halogens are monatomic elements e. The smell of the ocean is caused by atoms. 3. (6 pts) Write a word equation for the following using all appropriate symbols: Maryellen places an orange-red powder into a test tube and holds it over a flame for a minute or two. As she watches, a silvery-white substance forms droplets on the side of the tube while a brownish gaseous material escapes out of the tube. 4. (12 pts) a. Draw a representation of a mixture of nitrogen gas and neon gas in the box by using a circle to indicate a nitrogen atom and a dark circle to represent a neon atom. Place at least a total of 4 basic units in the box. b. State the Law of Conservation of Mass 1

2 PART II: Multiple Choice Place an x across the letter corresponding to the answer for each question (3 pts each). 5. a b c d 10. a b c d 6. a b c d 11. a b c d 7. a b c d 12. a b c d 8. a b c d 13. a b c d 9. a b c d 5. Which represents the nonmetal elements in Period 5? a. At, Rn b. Sb, Te c. B,i Po, At, Rn d. Te, Po 6. A compound is composed of a. all the same kind of atoms b. a physical mix of different kinds of atoms c. at least 2 different kinds of atoms bonded together d. at least 2 different kinds of molecules mixed together 7. Group 2A elements are also called: a. noble gases c. alkaline earth metals b. halogens d. alkali metals 8. Which among the following elements does not exist as a diatomic molecule in nature? a. Hydrogen c. Fluorine b. Nitrogen d. Neon 9. Which of the following represents an acid? a. bitter taste c. reacts with metals b. turns red litmus to blue d. two of the above 10. Which of the following statements is false? a. acids react with water to form neutrals c. bases have ph's above 7 b. acids react with metals d. soap is a base 11. A ph of 7 is represented by a. HC 2 H 3 O 2 c. NaOH b. soap d. water 12. A change in the ph of a solution from 4 to 6 means a. the solution is becoming less neutral c. a base has been added to the solution b. the solution is becoming more acidic d. the solution is becoming less basic 2

3 13. Concept attainment a. Involves yes/no questioning b. Allows students to generate a concept based on attributes c. Can only be used in science d. Provides hands-on experiences reflecting the steps of the scientific process PART III: Problems 15. (12 pts) The rusting of metals occurs when oxygen combines with a metal at a very slow pace to form rust. Terry has an old unopened box of iron nails that have completely rusted. The label indicates that the original weight of nails was g. He reweighs the contents of the box and finds the rusted nails now weigh g. a. Write a word equation for this reaction. b. Find the % composition of the rust. c. If the formula for rust is Fe 2 O 3, write an equation using formulas and balance it. d. What type of reaction is rusting? 3

4 PART I: Short Answer Name KEY Sec: 11am 1:30pm PH-218 Exam II Wednesday, October 12, (6 pts) Complete the following statements or answer the question. a. In the formula CaH 2 (NH 3 ) 2 (SO 4 ) 2 there are 21 total atoms. This molecule also has a total of 4 subunits. b. Name an element that is a liquid at room temperature. Hg or Br 2. (18 pts) True/False. Write true or false in front of each statement. a. false The reaction of baking soda and vinegar to produce carbon dioxide gas is an example of a precipitation reaction. b. false When water is heated, bubbles are formed in the water. This is evidence of a chemical reaction occurring. c. false PbS + Mg MgS + Pb is an example of a double replacement reaction. d. false Halogens are monatomic elements. e. true The smell of the ocean is caused by atoms. 3. (6 pts) Write a word equation for the following using all appropriate symbols: Maryellen places an orange-red powder into a test tube and holds it over a flame for a minute or two. As she watches, a silvery-white substance forms droplets on the side of the tube while a brownish gaseous material escapes out of the tube. Powder (s) 4. (12 pts) silvery substance (l) + brown material (g) a. Draw a representation of a mixture of nitrogen gas and neon gas in the box by using a circle to indicate a nitrogen atom and a dark circle to represent a neon atom. Place at least a total of 4 basic units in the box. b. State the Law of Conservation of Mass. In a chemical reaction the weight of the reactants is I always equal to the weight of the products. 4

5 PART II: Multiple Choice Place an x across the letter corresponding to the answer for each question (3 pts each). 5. a b c d 10. a b c d 6. a b c d 11. a b c d 7. a b c d 12. a b c d 8. a b c d 13. a b c d 9. a b c d 5. Which represents the nonmetal elements in Period 5? a. At, Rn b. Sb, Te c. B,i Po, At, Rn d. Te, Po 6. A compound is composed of a. all the same kind of atoms b. a physical mix of different kinds of atoms c. at least 2 different kinds of atoms bonded together d. at least 2 different kinds of molecules mixed together 7. Group 2A elements are also called: a. noble gases c. alkaline earth metals b. halogens d. alkali metals 8. Which among the following elements does not exist as a diatomic molecule in nature? a. Hydrogen c. Fluorine b. Nitrogen d. Neon 9. Which of the following represents an acid? a. bitter taste c. reacts with metals b. turns red litmus to blue d. two of the above 10. Which of the following statements is false? a. acids react with water to form neutrals c. bases have ph's above 7 b. acids react with metals d. soap is a base 11. A ph of 7 is represented by a. HC 2 H 3 O 2 c. NaOH b. soap d. water 12. A change in the ph of a solution from 4 to 6 means a. the solution is becoming less neutral c. a base has been added to the solution b. the solution is becoming more acidic d. the solution is becoming less basic 5

6 13. Concept attainment a. Involves yes/no questioning b. Allows students to generate a concept based on attributes c. Can only be used in science d. Provides hands-on experiences reflecting the steps of the scientific process PART III: Problems 14. (12 pts) The rusting of metals occurs when oxygen combines with a metal at a very slow pace to form rust. Terry has an old unopened box of iron nails that have completely rusted. The label indicates that the original weight of nails was g. He reweighs the contents of the box and finds the rusted nails now weigh g. a. Write a word equation for this reaction. Iron (s) + oxygen (g) rust (s) b. Find the % composition of the rust. Iron + oxygen rust wt O = g g = 53.78g (125.00g) +? = (178.78g) % O = 53.78/ x 100 = 30.08% O %Fe = / x 100 = % Fe c. If the formula for rust is Fe 2 O 3, write an equation using formulas and balance it. 4 Fe (s) + 2O 2(g) 2 Fe 2 O 3 d. What type of reaction is rusting? Synthesis 6