# Given a volume of mercury metal, how do I find its molar quantity?

Sep 25, 2016

You need to find (i) the mass of the sample, and (ii) convert this mass into a molar quantity.

#### Explanation:

$\rho , \text{density" = "mass"/"volume}$

You have a 15 mL volume of metal, and so $\text{mass "=" "rhoxx"volume} .$

And then you divide this mass by the molar mass of mercury to get an answer in moles: $\text{moles"="mass"/"molar mass} .$

The number of moles corresponds to a precise numerical quantity of mercury atoms. You need to use $\text{Avogadro's number}$.