# How many atoms of potassium are in 249 g of potassium sulfate?

Aug 14, 2017

Approx. $1.7 \times {10}^{24}$ individual potassium cations.....

#### Explanation:

We work out (i) the molar quantity of potassium sulfate:

$\frac{249 \cdot g}{174.26 \cdot g \cdot m o {l}^{-} 1} = 1.43 \cdot m o l$.

Stoichiometry INSISTS that if there are $1.43 \cdot m o l$ potassium sulfate, there are $2 \times 1.43 \cdot m o l = 2.86 \cdot m o l$ with respect to potassium ion.

And thus we multiply this molar quantity by ${N}_{A} ,$ $\text{the Avocado number}$....

"No. of potassium cations"=2.86*molxx6.022xx10^23*mol^-1=??