Quantitative Analysis

What is the percent by mass of magnesium in MgO?

• 20%
• 40%
• 50%
• 60%

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

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 empirical formula for the following:
Pb₅Cr₅O₂₀

• Pb₂Cr₂O₁₀
• PbCr₂O₇
• Pb₉Cr₄O₂
• PbCrO₄

A compound consists of 72.2% magnesium(Mg) and 27.8% nitrogen(N) by mass. What is the empirical formula?

• Mg₄N₃
• MgN₂
• Mg₃N₂ 
• MgN

Which of the following is considered an empirical formula?

• CH₃COOH
• C₆H₁₂O₆
• H₂O

What is the empirical formula if you have 81.82% carbon and 18.18% hydrogen?

• C3H8
• CH4
• C2H2
• C4H10

Which pair has the same empirical formula?

• NaCrO₄ and Na₂Cr₂O₇
• C₂H₄O₂ and C₆H₁₂O₆
• C₃H₆O₃ and C₂H₆O₂
• CH₄ and C₂H₆

A formula with the lowest whole # ratio of elements in a compound is called

• Molecular Formula
• Chemical Formula
• Empirical Formula 
• Distance Formula