# Given rho_"substance"=2.78*g*mL^-1, what volume is associated with a 32.0*g mass?

##### 1 Answer
Sep 15, 2017

$\rho , \text{Density"="Mass"/"Volume}$

#### Explanation:

I write the defining quotient because given two of the three properties, we can access the third by division or multiplication.....

Here we gots $\rho$, and we gots $\text{mass}$....

And so, clearly, we can calculate $\frac{\text{volume"="Mass}}{\rho}$

$\frac{32 \cdot \cancel{g}}{2.78 \cdot \cancel{g} \cdot m {L}^{-} 1} = 11.5 \cdot \frac{1}{m {L}^{-} 1} = 11.5 \cdot \frac{1}{\frac{1}{m L}} = 11.5 \cdot m L$....

Such an operation is also consistent dimensionally, which is why I include the units of each property. We want an answer with units of density, $\text{mass per unit volume}$; the quotient gave us an answer with units $\text{mass per unit volume}$, so we cannot be too far wrong.