# How can I calculate the amount of matter in a given volume?

Aug 9, 2014

Use the density equation: density = mass/volume.

#### Explanation:

The amount of matter in a substance is its mass. In order to calculate the amount of matter in a given volume of a sample, you will use the density equation: density = mass/volume.

To find mass using the density equation, you must know the volume of your sample and its density. In this example, I'm going to use the element copper. The density of the elements are known and can be looked up in charts.

To find mass from density and volume, manipulate the equation so that mass = (density)(volume).

Example: What is the mass of a sample of copper that has a volume of $8.00 c {m}^{3}$?

Known or Given:
Cu volume = $8.00 c {m}^{3}$
density of copper at ${20}^{\text{o}}$C = $8.96$g/$c {m}^{\text{3}}$
http://www.chemicalelements.com/elements/cu.html

Equation:
density = mass/volume

Solution:
mass = (density)(volume) = ($8.96$g/$c {m}^{\text{3}}$)($8.00 c {m}^{3}$) = 1.12g Cu