# How many formula units are present in a #12.6*g# mass of #MgCl_2#?

##### 1 Answer

Jun 17, 2017

Approx.

#### Explanation:

We find the molar quantity by dividing the mass of substance by the molar mass.....

How did I get the

And this there are

But a mole is SIMPLY A NUMBER, i.e.

And so the number of formula units.........

How many magnesium atoms, and how many chlorine atoms?