Choose the pair that is an empirical and molecular formula of one another.

• NaCrO₄ and Na₂Cr₂O₇

• CH₂O and C₆H₁₂O₆

• C₃H₆O₃ and C₂H₆O₂

• CH₄ and C₂H₆

C₂H_4.

What is the empirical formula?

• CH

• CH₂

• C₄H₂

• C₂H₄

C₄H₆

What is the empirical formula?

• CH

• CH₃

• C₂H₃

• C₄H₆

Given the potential energy diagram of a chemical reaction: Which term best describes the reaction?

• exothermic
• endothermic
• sothermic
• nuclear  

Which of the following could be classified as an empirical formula?

• C₂H₄

• CH₂

• C₃H₁₂

• C₂H₈

Br₂O₆

What is the empirical formula?

• BrO₃

• Br₆O₂

• BrO

• Br₂O₆

What is the percentage of iron in iron(III)oxide?

• 30%
• 70%
• 40%
• 60%

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 empirical formula of the following molecular formula:  C₃H₆

• C₃H₆
• CH₂
• C₂H₄
• CH₃

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

• K₂SO₄ 
• K₈SO₁₆
• K₈S₄O₈ 
• K₈S₄O₁₆