2.7: Practice with Density
 Page ID
 235836
Exercise \(\PageIndex{1}\)
What is the density of a material if a sample with a mass of 45.82 g takes up a volume of 8.75 mL?
 Answer

5.24 g/mL
What mass would a sample of 32.6 cm^{3} of copper be? The density of copper is 8.96 g/cm^{3}.
 Answer

292 g
What volume of acetone would have a mass of 142.5 g? The density of acetone is 0.784 g/mL.
 Answer

182 mL
Exercise \(\PageIndex{1}\)
An empty beaker has a mass of 65.873 g. You add 23.8 mL of solution, and the beaker now has a mass of 85.347 g. What is the density of your solution?
 Answer

0.818 g/mL
You have a rectangular block of metal that measures 4.82 cm long, 3.44 cm wide, and 2.65 cm high. The mass is 197.7 g. What is the density of the metal?
 Answer

4.50 g/cm^{3}
To a graduated cylinder with 22.5 mL of water you add 38.95 g of metal pieces. The water level rises to 28.0 mL. What is the density of the metal?
 Answer

7.1 g/mL
Exercise \(\PageIndex{1}\)
You have a copper metal cylinder that is 5.80 cm high. The diameter of the cylinder is 1.44 cm. What would the mass of this cylinder be? The density of copper is 8.96 g/cm^{3}. The formula to calculate the volume of a cylinder is \(V = (\pi)r^2h\), where \(r\) is the radius (half the diameter) and \(h\) is the height. If your calculator doesn't have a button for pi, use the value \(\pi = 3.14159\).
 Hint

The volume of the cylinder is 9.45 cm^{3}. (9.44589... cm^{3} with 3 significant figures)
 Answer

84.6 g (If you round the volume to 9.45 cm^{3}, you get 84.7 g. If you keep the digits in your calculator and round at the very end, it is 84.6 g.)
You have a graduated cylinder with the water level at 30.8 mL. You add 72.88 g of copper to the water. The density of copper is 8.96 g/cm^{3}. What is the final water level?
 Hint

The volume of copper added is 8.13 cm^{3}, which equals 8.13 mL.
 Answer

38.9 mL is the water level after the copper is added.
Before you add acetone to a beaker, the mass is 59.43 g. After you add the acetone, the mass is 81.09 g. The density of acetone is 0.784 g/mL. What volume of acetone is in the beaker?
 Hint

The mass of acetone added is 21.66 g.
 Answer

27.6 mL