A salt is analyzed and found to contain 0.92*g0.92g of sodium, 1.42*g1.42g of chlorine, and 2.56*g2.56g of oxygen. What is the empirical formula of this salt?

1 Answer
Apr 30, 2017

Well, we find the molar quantities of each constituent.........to get an empirical formula of NaClO_4NaClO4.

Explanation:

"Moles of sodium"Moles of sodium == (0.92*g)/(22.99*g*mol^-1)=0.0400*mol0.92g22.99gmol1=0.0400mol

"Moles of chlorine"Moles of chlorine == (1.42*g)/(35.45*g*mol^-1)=0.0400*mol1.42g35.45gmol1=0.0400mol.

"Moles of oxygen"Moles of oxygen == (2.56*g)/(15.99*g*mol^-1)=0.160*mol2.56g15.99gmol1=0.160mol.

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_4NaClO4; and this is "sodium perchlorate"sodium perchlorate,