Test your separation of mixtures memory by trying the activities below:

**Density Problems**

Click on the words *Hint* and *Answer* to check your solution.

Given a mass of 14 g and a volume of 28 mL, calculate the density.

## Hint

D= m/v

## Answer

D = m/v = 14 g/28 mL = 0.50 g/mL

What is the mass of an object with a density of 4.0 g/cm^{3} that displaces 3.0 cm^{3} of water?

## Hint

m = DxV

Given that the density of iron is 11.35 grams per centimeter cubed, what would be the volume of a 1.1 gram piece of iron?

## Hint

v = m/D

## Answer

V = m/D = 1.1 g/(11.35 g/cm^{3}) = 0.097 cm^{3}

Find the density of a block with a length of 8.0 cm, a width of 4.0 cm, a height 2.0 cm, and a mass of 32 g. Would this block float or sink in water?

## Hint

D = m/v ; Density of water is 1 g/cm^{3}

## Answer

Density of block is D = m/v = 32 g/(8 cm x 4 cm x 2 cm) = 32 g/64 cm^{3} = .5 g/cm^{3}; Density of block < density of water: block would float

You have two pieces of jewelry. One of them is supposed to be pure silver. The first piece has a mass of 20.0 g and the other piece has a mass of 44.0 g. Both pieces displace 4.0 mL of water. Silver has a density of 10.5 g/cm^{3}. Which piece is actually silver?

## Hint

D = m/v

## Answer

20/4 = 5 and 44/4 = 11 If one has to be silver, it’s likely the second one.

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