TEST BANK FOR PRINCIPLES OF GENERAL CHEMISTRY, 3RD EDITION: MARTIN SILBERBERG

Chapter 1 Keys to the Study of Chemistry 1. Which one of the following is a "substance" in the sense of the word as used in your textbook? A) air B) tap water C) sea water D) water E) toothpaste Ans: D 2. Select the best statement. A) Physical changes may be reversed by changing the temperature. B) Physical changes alter the composition of the substances involved. C) Physical properties are not valid characteristics for identifying a substance. D) Physical properties are mostly extensive in nature. E) Physical changes are usually accompanied by chemical changes. Ans: A 3. Select the best statement. A) Chemical changes provide the only valid basis for identification of a substance. B) Chemical changes are easily reversed by altering the temperature of the system. C) Chemical changes always produce substances different from the starting materials. D) Chemical changes are associated primarily with extensive properties. E) Chemical changes are accompanied by changes in the total mass of the substances involved. Ans: C 4. Which of the following is a chemical change? A) boiling of water D) condensing water vapor into rainfall B) melting wax E) carving a piece of wood C) broiling a steak on a grill Ans: C 5. Water vapor is less dense than ice because A) molecules in the gas phase are in constant motion. B) molecules in the gas phase have more potential energy than in solids. C) molecules in the gas phase have more kinetic energy than in solids. D) gaseous molecules have less mass. E) molecules in the gas phase have more space between them than in solids. Ans: E