Empirical/Molecular Formula

Find the empirical formula for a compound which contains 32.8% chromium and 67.2% chlorine.

• CrCl

• CrCl₃

• Cr₃Cl

• Cr₂Cl₆

A compound contains 18.8% Na, 29.0% Cl, and 52.5% O by mass. Determine the empirical formula.

• NaClO

• NaClO₄

• Na₂Cl₂O₈

• NaCl₂O₄

Tags

NGSS.HS-PS1-1

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 pair has the same empirical formula?

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

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

• Molecular Formula

• Chemical Formula

• Empirical Formula

• Distance Formula

Glycerol has a molar mass of 92.09g/mol. Its percent composition is: 39.12% C, 8.75% H, and 51.12% O. What is the molecular formula for glycerol?

• C₂H₃O₂
• CH₂O
• C₂H₄O₂
• C₃H₈O₃

What is the molecular formula for a compound with the empirical formula: K₂SO₄ and a molecular mass of 696g.

EF = CF₂ 
Molecular formula mass = 192
MF =

• C₄F₈
• C₄F
• CF₈
• C₂F₄

?

• CH₄N₂0
• CH₄N0
• CHN₂0
• C₂H₄N₂0₈

What do you do when you get a half in the ratio?

• add 2 to each element
  add two to only the one with the half
• multiply the one with the half only by two
• multiply all of them by two
• add two to all of the ratios