# How many molecules are present in 5 g of CuSO_4 * 5H_2O?

Dec 11, 2016

In $\text{copper sulfate pentahydrate}$, well there are $0.020$ $m o l$ of stuff in $5 \cdot g$.

#### Explanation:

$\text{Moles of}$ $C u S {O}_{4} \cdot 5 {H}_{2} O$ $=$ $\frac{5 \cdot g}{249.67 \cdot g \cdot m o {l}^{-} 1} = 0.020 \cdot m o l .$

There are thus $0.020 \cdot m o l$ $C u , \mathmr{and} S$ atoms. There are $9 \times 0.020 \cdot m o l$ oxygen atoms, and there are $10 \times 0.020 \cdot m o l$ hydrogen atoms.

Note that I am dealing with atoms not molecules.