The density of a sample of aluminum is 2.70 g/cm3. You submerse a sample of aluminum in water, and the volume of the water rises 1.3 L (1.3 L is displaced by the aluminum). Using the correct number of significant figures, what is the mass of the sample?

1 Answer
Oct 16, 2016

The mass of aluminum is 3500 g, rounded to two significant figures.

Explanation:

Density is mass per unit of volume.

#"density"="mass"/"volume"#

The displaced volume of water is the volume of the aluminum sample.

Since the given density is in #"g/cm"^3#, the unit for the volume of water needs to be converted to #"cm"^3#.

#"1 L=1000 mL"#
#"1 mL=1 cm"^3"#

#1.3cancel"L"xx(1000cancel"mL")/(1cancel"L")xx(1"cm"^3)/(1cancel"mL")="1300 cm"^3"#

In order to determine the mass of an object when its density and volume are known, the equation needs to be rearranged to isolate #"mass"#

#"mass"="density"xx"volume"#

Substitute the given density and volume into the equation and solve.

#"mass"=2.70"g"/cancel"cm"^3xx1300cancel"cm"^3"=3510 g"=3500 "g"# rounded to two significant figures