chm2045exam2 - Che 2045Exam #2 Return periodic

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Chem 2045Exam #2 Return periodic table 1. According to the following unbalanced reaction, when 45.0 g of calcium are consumed, how  much O 2  is also required?  Ca(s) + O 2  (g)   CaO(s) A) 9.00 g  B) 18.0 g  C) 36.0 g  D) 72.0 g    answer:   B    2. Which of the following 1.00 g samples has the smallest mass of O? A) SO 2   B) H 2 C) CO 2   D) O 3    answer:   A    3. What is the formula weight of Mg 3 (PO 4 ) 2  ? A) 118.3 g/mol  B) 167.9 g/mol  C) 262.9 g/mol  D) 362.5 g/mol    answer:   C    4. What is the formula weight of nitric acid? A) 31.0 g/mol  B) 47.0 g/mol  C) 63.0 g/mol  D) 79.0 g/mol    answer:   C    5. Copper has two naturally occurring isotopes, Cu-63 (62.94 amu) and Cu-65 (64.93 amu). What is the approximate percent abundance of  each copper isotope? A) 70 % Cu-63 and 30 % Cu-65  B) 30 % Cu-63 and 70 % Cu-65  C) 45 % Cu-63 and 55 % Cu-65 D) 55 % Cu-63 and 45 % Cu-65    answer:   A    6. Aluminum cans have a long environmental lifetime because Al forms a stable oxide coating that adheres to the metal. What is the weight  % of Al in aluminum oxide? A) 38.2 % 
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This document was uploaded on 11/02/2011 for the course CHM 2045 at University of Florida.

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chm2045exam2 - Che 2045Exam #2 Return periodic

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