A salt is analyzed and found to contain 0.92*g of sodium, 1.42*g of chlorine, and 2.56*g of oxygen. What is the empirical formula of this salt?

Apr 30, 2017

Well, we find the molar quantities of each constituent.........to get an empirical formula of $N a C l {O}_{4}$.

Explanation:

$\text{Moles of sodium}$ $=$ $\frac{0.92 \cdot g}{22.99 \cdot g \cdot m o {l}^{-} 1} = 0.0400 \cdot m o l$

$\text{Moles of chlorine}$ $=$ $\frac{1.42 \cdot g}{35.45 \cdot g \cdot m o {l}^{-} 1} = 0.0400 \cdot m o l$.

$\text{Moles of oxygen}$ $=$ $\frac{2.56 \cdot g}{15.99 \cdot g \cdot m o {l}^{-} 1} = 0.160 \cdot m o l$.

Note that I DIVIDED THRU BY the ATOMIC MASS of each constituent. And now, we divide thru by the SMALLEST molar quantity, that of sodium, to get an empirical formula of $N a C l {O}_{4}$; and this is $\text{sodium perchlorate}$,