Name: 
 

Percent Comp



Multiple Choice
Identify the letter of the choice that best completes the statement or answers the question.
 

 1. 

What information is needed to calculate the percent composition of a compound?
a.
the weight of the sample to be analyzed and its density
b.
the weight of the sample to be analyzed and its molar volume
c.
the formula of the compound and the atomic mass of its elements
d.
the formula of the compound and its density
 

 2. 

If 60.2 grams of Hg combines completely with 24.0 grams of Br to form a compound, what is the percent composition of Hg in the compound?
a.
28.5%
c.
71.5%
b.
39.9%
d.
60.1%
 

 3. 

What is the percent composition of chromium in BaCrOch10percentcomp_files/i0040000.jpg?
a.
4.87%
c.
20.5%
b.
9.47%
d.
25.2%
 

 4. 

If 20.0 grams of Ca combines completely with 16.0 grams of S to form a compound, what is the percent composition of Ca in the compound?
a.
1.25%
c.
44.4%
b.
20.0%
d.
55.6%
 

 5. 

What is the percent composition of carbon, in heptane, Cch10percentcomp_files/i0060000.jpgHch10percentcomp_files/i0060001.jpg?
a.
12%
c.
68%
b.
19%
d.
84%
 

 6. 

What is the percent by mass of carbon in acetone, Cch10percentcomp_files/i0070000.jpgHch10percentcomp_files/i0070001.jpgO?
a.
20.7%
c.
1.61%
b.
62.1%
d.
30.0%
 

 7. 

Which expression represents the percent by mass of nitrogen in NH4NO3?
a.
14 g N/80 g NHch10percentcomp_files/i0080000.jpgNOch10percentcomp_files/i0080001.jpg ch10percentcomp_files/i0080002.jpg 100%
c.
80 g NHch10percentcomp_files/i0080003.jpgNOch10percentcomp_files/i0080004.jpg/14 g N ch10percentcomp_files/i0080005.jpg 100%
b.
28 g N/80 g NHch10percentcomp_files/i0080006.jpgNOch10percentcomp_files/i0080007.jpg ch10percentcomp_files/i0080008.jpg 100%
d.
80 g NHch10percentcomp_files/i0080009.jpgNOch10percentcomp_files/i0080010.jpg/28 g N ch10percentcomp_files/i0080011.jpg 100%
 

 8. 

Which of the following compounds has the lowest percent gold content by weight?
a.
AuOH
c.
AuClch10percentcomp_files/i0090000.jpg
b.
Au(OH)ch10percentcomp_files/i0090001.jpg
d.
AuIch10percentcomp_files/i0090002.jpg
 

 9. 

Which of the following compounds has the highest oxygen content, by weight?
a.
Nach10percentcomp_files/i0100000.jpgO
c.
BaO
b.
COch10percentcomp_files/i0100001.jpg
d.
Hch10percentcomp_files/i0100002.jpgO
 

Short Answer
 

 10. 

What is the percent composition of NiO, if a sample of NiO with a mass of 41.9 g contains 33.1 g Ni and 8.8 g O?
 

 11. 

What is the percent by mass of hydrogen in aspirin, Cch10percentcomp_files/i0130000.jpgHch10percentcomp_files/i0130001.jpgOch10percentcomp_files/i0130002.jpg?
 



 
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