# A rock has a density of 4 g/mL and a mass of 16 grams. What is the volume this rock occupies?

##### 1 Answer

#### Explanation:

The **density** of the rock essentially tells you the mass of *one unit of volume* of that rock.

In this case, a density of *milliliters*, has a mass of

You know that the rock has a mass of

#"4 g/mL" = "4 grams"/"1 mL"#

as a **conversion factor** to help you figure out its volume.

To do that, rearrange the density to have the mass **as the denominator** and the volume as the **numerator** and multiply the resulting fraction by the mass of the rock.

You will have

#16 color(red)(cancel(color(black)("g"))) * "1 mL"/(4color(red)(cancel(color(black)("g")))) = color(green)(bar(ul(|color(white)(a/a)color(black)("4 mL")color(white)(a/a)|)))#

The answer is rounded to one **sig fig**.