# Question a760d

Feb 18, 2017

Here's how you can do that.

#### Explanation:

All you have to do here is use the fact that density is defined as mass per unit of volume.

In essence, the density of a substance tells you the mass of exactly one unit of volume of said substance. This means that you can find the density of a substance by diving the mass of a given sample by the volume it occupies

$\textcolor{b l u e}{\underline{\textcolor{b l a c k}{\rho = \frac{m}{V}}}}$

Here

• $\rho$ is the density of the substance
• $m$ is the mass of the sample
• $V$ is the volume it occupies

In order to find the mass of a sample, rearrange the above equation to isolate $m$

$\rho = \frac{m}{V} \implies m = \rho \cdot V$

Now, let's say that a substance has a density equal to $x$ ${\text{g mL}}^{- 1}$ and that a sample of this substance occupies a volume of $y$ $\text{mL}$.

You can say that the mass of this sample is equal to

m = x color(white)(.)"g" color(red)(cancel(color(black)("mL"^(-1)))) * y color(red)(cancel(color(black)("mL")))#

$m = \left(x \cdot y\right) \text{ g}$