# What is the density of a substance if a sample of 375 mL has a mass of 450 grams?

##### 1 Answer

#### Explanation:

As you know, density is defined as mass **per unit of volume**.

#color(blue)("density" = "mass"/"unit of volume")#

This means that your goal when asked to find a substance's density will be to find the mass of **one unit of volume** of that substance.

In your case, the sample is said to have a volume of *unit of volume* will be

Well, you know that a volume of *packed* per unit of volume, you can safely assume that it will be **constant** for a substance as long as temperature and pressure are kept constant.

This means that you can write

#1 color(red)(cancel(color(black)("mL"))) * "450 g"/(375 color(red)(cancel(color(black)("mL")))) = "1.2 g"#

So, if

#"density" = rho = "1.2 g"/"1 mL" = color(green)("1.2 g/mL") -># rounded to two sig figs