Learn the toughest concepts covered in your GOB - General, Organic, and Biological Chemistry class with step-by-step video tutorials and practice problems.

Solutions

**Freezing Point Depression** is the phenomenon when adding a solute to a pure solvent results in decreased freezing point of the solvent.

1

Freezing Point Depression Concept 1

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2

Freezing Point Depression Example 1

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3

Problem

How many moles of ethylene glycol, C_{2}H_{6}O_{2}, must be added to 1,000 g of water to form a solution that has a freezing point of – 10ºC?

A

334 moles

B

5.4 moles

C

3.2 moles

D

200 moles

4

Problem

An ethylene glycol solution contains 28.3 g of ethylene glycol, C_{2}H_{6}O_{2} in 97.2 mL of water. Calculate the freezing point of the solution. The density of water 1.00 g/mL.

A

–8.72°C

B

–0.848°C

C

–0.541°C

D

–17.4°C

5

Problem

When 825 g of an unknown is dissolved in 3.45 L of water, the freezing point of the solution is decreased by 2.89ºC. Assuming that the unknown compound is a non-electrolyte, calculate its molar mass.

A

154 g/mol

B

42.4 g/mol

C

44.5 g/mol

D

159 g/mol