6. Empirical & Molecular Formula -1

What is the empirical formula for hydrogen peroxide which has a molecular formula of H₂O₂?

• HO

• H₂O₂

• H₂O

The empirical formula for a compound is CH₂ and its relative atomic mass (A_r) is 70. What is its molecular formula? Use the periodic table to help you.

• CH₂

• C₅H₁₀

• C₇₀H₁₄₀

If 2.8 g of nitrogen combines with 6.4 g of oxygen, what is the empirical formula of the nitrogen oxide formed? Use the periodic table to help you.

• NO

• N₂O

• NO₂

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

• 20%
• 27%
• 46%
• 53%

Which pair has the same empirical formula?

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

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

• Mg₄N₃
• MgN₂
• Mg₃N₂ 
• MgN

You are given the following percentages: 40.05% S and 59.95% O. Find the empirical formula for these elements.

• SO
• SO2
• SO3
• SO4

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

• C3H8
• CH4
• C2H2
• C4H10

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

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

Given the following: 42.07% Na, 18.89% P, and 39.04% O, determine the empirical formula.

•  NaPO2
• Na2PO3
• Na3PO4
• NaPO4