# How many moles of MgI_2 will you have if you have 345.0 g of it?

A bit over $1$ $m o l$.
$\text{Number of moles}$ $=$ $\text{Mass"/"Molar Mass}$
$=$ $\frac{345.0 \cdot g}{278.11 \cdot g \cdot m o {l}^{-} 1}$ $=$ ??mol.