In order to find mass when you have and volume, you use the relationship

##”Density” = “Mass”/”Volume”##

You multiply both sides of the equation by the volume and get:

##”Mass ” = ” Volume × Density”##

Here are two example calculations:

Example 1

A piece of aluminum has a volume of ##”6.0 cm”^3## and a density of ##”2.70 g/cm”^3##. What is its mass?

Solution

##”Mass” = 6.0 cancel(“cm”^3) × “2.70 g”/(1 cancel(“cm”^3)) = “16.2 g”##

##” “##

Example 2

Calculate the mass of ##”30.0 mL”## of methanol, if the density of methanol is ##”0.790 g/mL”##.

Solution

##”Mass” = 30.0 cancel(“mL”) × “0.790 g”/(1 cancel(“mL”)) = “23.7 g”##