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?

1 Answer
Apr 30, 2017

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"#,