Unit 7: Molecular Formula and Hydrates

Multiple Choice

What is the molecular formula if the empirical formula is CH₂O and the molecular molar mass is 180.18?

• CH₂O
• C₂H₄O₂
• C₄H₈O₄
• C₆H₁₂O₆

Multiple Choice

EF = CF₂ 
Molecular formula mass = 192
MF =

• C₄F₈
• C₄F
• CF₈
• C₂F₄

Multiple Choice

A compound is a hydrate when it...

• a substance is completely dehydrate, removig all water

• Set number of salt molecules loosely bonded to an ionic compound

• Set number of water molecules loosely bonded to an ionic compound

• repels water from the compound

Multiple Choice

Name the following ionic compound: MgSO₄*7H₂O

• magnesium sulfate dihydrate

• magnesium sulfate hexahydarte
• magnesium sulfate heptahydrate

Multiple Choice

Na₂CO₃ · 10H₂O is known as sodium carb ______

• Hydroxide
• Hydrate
• Decahydrate
• None of the above

Multiple Choice

A 15.67 g sample of a hydrate of magnesium carbonate was heated to drive off the water. The mass was reduced to 7.58 g. What is the formula of the hydrate?

• MgCO₃ · 5H₂O
• MgCO₃ · 4H₂O
• MgCO₃ · 6H₂O
• MgCO₃ · 1H₂O