Question

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?

Answer 1

Well, we find the molar quantities of each constituent.........to get an empirical formula of `NaClO_4`.

Explanation:

`"Moles of sodium"` `=` `(0.92*g)/(22.99*g*mol^-1)=0.0400*mol`

`"Moles of chlorine"` `=` `(1.42*g)/(35.45*g*mol^-1)=0.0400*mol`.

`"Moles of oxygen"` `=` `(2.56*g)/(15.99*g*mol^-1)=0.160*mol`.

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 `NaClO_4`; and this is `"sodium perchlorate"`,