# How do you determine the mass of potassium in 33.5 g of KCl?

Jul 21, 2017

Mass of potassium = $17.569 g$
Molar mass of KCl = $74.5513 g \cdot m o {l}^{-} 1$
Moles of KCl in the given sample = $\frac{33.5}{74.5513} m o l$
We can easily see that $x$ mol of KCl contains $x$ mol of potassium atoms
Mass of potassium in given sample = moles of K $\times$ molar mass of K =$\frac{33.5}{74.5513} \times 39.0983$ = $17.569 g$