What is the empirical formula of a compound that contains 50.0% carbon, 6.7% hydrogen, and 43.3% oxygen by mass?

1 Answer
Apr 25, 2016

Answer:

#C_3H_5O_2#

Explanation:

We assume #100# #g# of unknown compound.

There are thus #(50.0*g)/(12.011*g*mol^-1)# #=# #4.163# #mol*C#.

And #(6.7*g)/(1.00794*g*mol^-1)# #=# #6.65# #mol*H#.

And #(43.3*g)/(15.999*g*mol^-1)# #=# #2.71# #mol*O#.

We divide thru by the lowest molar quantity, that of oxygen to get a formula of #C_(1.54)H_(2.45)O_(1)#, which we double to give a whole number EMPIRICAL formula of #C_3H_5O_2#.