8C Percent Composition

What is the percent composition of oxygen in MgO?

• 20%

• 40%

• 50%

• 60%

What is the percent composition of sodium in NaCl?

• 39%

• 61%

• 35%

• 65%

What is the percent composition of sulfur in the compound MgSO₄?

• 20%

• 27%

• 46%

• 53%

What is the percent composition of Benzene, C₆H₆?

• C = 50%
  H = 50%
• C = 85.7 %
  H = 14.3%
• C = 92.2%
  H = 7.8%
• C = 71.9%
  H = 28.1%

Tags

NGSS.HS-PS1-1

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)

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 percentage of the total atomic mass of lithium phosphide (Li₃P) is composed of phosphorus?

• 13%

• 29%

• 40%

• 60%

What percentage of the total atomic mass of lithium phosphide (Li₃P) is composed of lithium? Hint - consider all three atoms of lithium in your calculation.

• 13%

• 29%

• 40%

• 60%