Percent Composition

What is the percent by mass of sodium in NaCl?

• 39%

• 61%

• 35%

• 65%

What is the percent by mass of magnesium in MgO?

• 20%

• 40%

• 50%

• 60%

What is the percent composition by mass of magnesium in the compound MgSO₄ (gram formula mass = 120 g/mol)?

• 20%

• 27%

• 46%

• 53%

What is the percent composition by mass of oxygen in the compound MgSO₄ (gram formula mass = 120 g/mol)?

• 20%

• 27%

• 46%

• 53%

What is the percent by mass of Cu in CuBr₂?

• 50%

• 71.6%

• 28.4%

• 44.3%

Tags

NGSS.HS-PS1-7

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%

What is the percent composition by mass of sulfur (S) in the compound MgSO₄?

• 20.22%

• 19.85%

• 26.64%

• 28.64%

A student calculated the number of moles of methane (CH4) present in a 100g sample of a gaseous mixture. If the student determined that there’s 0.6 moles of methane present in the sample, what is the percent composition of methane in the sample?

• .096%

• 9.6%

• .9%

• 90%

What is the percent composition of the elements in Benzene, C₆H₆?

• C = 50%

  H = 50%

• C = 85.7 %

  H = 14.3%

• C = 92.2%

  H = 7.8%

• C = 71.9%

  H = 28.1%

which one defines percent composition?

• the percent by mass of each element in a compound

• when elements join together

• when water dries up

• elements split