Questions and Answers on Chemistry: The Study of Change Essay

7241 Words Jan 23rd, 2012 29 Pages
Chapter 1: Chemistry: The Study of Change

1. A tentative explanation for a set of observations that can be tested by further experimentation is referred to as A) a hypothesis. B) a law. C) a theory. D) none of the above. Ans: A Category: Easy Section: 1.3

2. A concise verbal or mathematical statement of a relationship between phenomena that is always the same under the same conditions is referred to as A) a hypothesis. B) a law. C) a theory. D) none of the above. Ans: B Category: Easy Section: 1.3

3. A unifying principle that explains a body of facts and relations is referred to as A) a hypothesis. B) a law. C)
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E) Sodium is never found as the pure metal in nature. Ans: B Category: Easy Section: 1.6

12. All of the following are properties of tin. Which one is a chemical property of tin? A) Tin can be hammered into a thin sheet. B) At –40°C a sheet of tin crumbles to a gray powder. C) Tin melts at 231.9°C. D) When a bar of tin is bent, it emits an audible “cry”. E) Tin erodes when added to hydrochloric acid, and a clear gas forms. Ans: E Category: Medium Section: 1.6

13. Which one of the following represents a chemical change? A) boiling water to form steam B) burning a piece of coal C) heating lead until it melts D) mixing iron filings and sand at room temperature E) breaking glass Ans: B Category: Medium Section: 1.6

14. Which of the following does not represent a chemical change? A) a freshly cut apple turns brown B) milk turns sour on standing at room temperature C) when cooled to 0°C, liquid water becomes ice D) frying an egg E) fermentation of sugar to alcohol Ans: C Category: Easy Section: 1.6

15. The SI prefixes nano and deci represent, respectively: A) 10–9 and 10–6. D) 109 and 10–6. B) 106 and 10–3. E) 10–9 and 10–1.