# A small beaker contains 55.0 mL of water. What would be the mass of the water?

Jun 30, 2018

Surely it would be $55 \cdot g$?

#### Explanation:

For water, ${\rho}_{\text{density}} = 1.0 \cdot g \cdot m {L}^{-} 1$...

And thus the product...$\rho \times \text{volume"="mass}$

$\equiv 1.0 \cdot g \cdot \cancel{m {L}^{-} 1} \times 55 \cdot \cancel{m L} \equiv 55.0 \cdot g$...

...this is an example of dimensional analysis where we include the units in the calculation in order to inform us whether we divide or multiply...by definition...${\rho}_{\text{density"="mass"/"volume}}$...