WorksheetsPercent Composition
Total questions: 25
Worksheet time: 25mins
What percentage of the total atomic mass of carbon monoxide (CO) is composed of carbon?
29%
43%
57%
73%
What percentage of the total atomic mass of carbon monoxide (CO) is composed of oxygen?
29%
43%
57%
73%
What percentage of the total atomic mass of magnesium bromide (MgBr2) is composed of bromine? Hint - consider the mass of both atoms of bromine in your calculation.
13%
43%
63%
87%
What percentage of the total atomic mass of lithium phosphide (Li3P) is composed of phosphorus?
13%
29%
40%
60%
Find the percent composition of Aspirin C9H8O4?
C
60%
H
4.4%
O
35.6%
Molar Mass of Aspirin
180 g/mol
Molar Mass of C9
108 g/mol
(Page 38-40) Percent Composition is the (a) by (b) of each element in a compound.
percentage
mass
compound
Complete the formula for % Composition.
mass of element
total mass of compound
100
Complete the formula for % Composition.
mass of element
total mass of compound
100
The percent, by weight, of carbon in C₄H₈O₃ is (a) .
55%
72%
31%
46%
What percentage of the total atomic mass of calcium nitrate (Ca(NO3)2) is composed of nitrogen? Hint - another way to think of calcium nitrate is Ca(NO3)(NO3).
17%
24%
29%
59%
What is the percent composition by mass of sulfur in the compound MgSO4 (gram formula mass = 120 g/mol)?
20%
27%
46%
53%
In which compound is the percent composition by mass of Cl equal to 42%?
HClO (gram formula mass = 52 g/mol)
HClO2 (gram formula mass = 68 g/mol)
HClO3 (gram formula mass = 84 g/mol)
HClO4 (gram formula mass = 100 g/mol)
Find the percent composition of Cu2S?
%Cu= 67.987 %S= 32.013
%Cu= 79.854 %S= 20.145
%Cu= 35.946 %S= 64.054
Find the percentage composition of Mg in Mg3(PO4)2.
27.48% Mg
43.11% Mg
16.00% Mg
12.63% Mg
What is the percent by mass of fluorine in CaF2 (gram-formula mass = 78 g/mol)?
24%
49%
51%
65%
Find the percent composition of CaCl2?
Ca: 36.11%; Cl: 63.88%
Ca: 53.12%; Cl: 100%
Ca: 36.11%; Cl: 83.56%
Ca: 46.11%; Cl: 63.88%
What percentage of the total atomic mass of water (H2O) is composed of hydrogen?
11%
22%
33%
44%
Calculate the percent composition of nitrogen in ammonium nitrate (NH4NO3).
28%
35%
42%
50%
What is the percent composition by mass of oxygen in carbon dioxide (CO2)?
27%
50%
73%
89%
Determine the percent composition of sodium in sodium chloride (NaCl).
23%
39%
61%
77%
What percentage of the total atomic mass of glucose (C6H12O6) is composed of carbon?
20%
40%
60%
80%
Find the percent composition of sulfur in sulfuric acid (H2SO4).
16%
32%
48%
64%
What is the percent by mass of chlorine in potassium chloride (KCl)?
24%
48%
60%
76%
Calculate the percent composition of iron in iron(III) oxide (Fe2O3).
30%
50%
70%
90%
What percentage of the total atomic mass of acetic acid (CH3COOH) is composed of hydrogen?
4%
8%
12%
16%
