# What is the mass of 2.30 x 10^24 formula units of magnesium chloride?

Nov 20, 2016

$\text{Mass}$ $\cong$ $380 \cdot g$

#### Explanation:

Here we use ${N}_{A}$, $\text{Avogadro's number}$ as our counting number, where ${N}_{A} = 6.022 \times {10}^{23} \cdot m o {l}^{-} 1$.

$\text{Avogadro's number}$ of $M g C {l}_{2}$ formula units have a mass of $95.21 \cdot g$. Alternatively we say the molar mass of $M g C {l}_{2}$ is $95.21 \cdot g \cdot m o {l}^{-} 1$.

So we work out the quotient,

$\frac{2.30 \times {10}^{24}}{6.022 \times {10}^{23} \cdot m o {l}^{-} 1} \times 95.21 \cdot g \cdot m o {l}^{-} 1 \cong 4 \times 95.21 \cdot g$