# What is the molarity of a solution that contains 50.0 g of Mg(NO_3)_2 per 225 mL of solution?

Jul 4, 2016

$1.50 M$

#### Explanation:

To find the molarity, the following equation must be used:

We are given the mass and volume of the solution, but both have bad units.

The mass of $M g {\left(N {O}_{3}\right)}_{2}$ can be converted into moles by using its molar mass (148.3 g/mol) as a conversion factor:

$50.0 \cancel{g} \times \frac{1 m o l}{148.3 \cancel{g}}$ $= 0.337 m o l$

Now we can convert 225 mL into L by multiplying 225 by 0.001 to obtain 0.225L.

All we do now is divide the number of moles by the volume to acquire the molarity:

$M = \frac{0.337 m o l}{0.225 L}$ = 1.50 M