2.38g uranium was heated strongly in a current of air. the resulting oxide weighted 2.806 g. determine the empirical formula of the oxide?
A) U4O8
B) U3O8
C) U9O5
D) U1O9
No. of mol of U = 2.38 /238 = 0.01
No. of mol of O= (2.806-2.38)/16 = 0.426/16 =0.0266
Ratio of moles of U and O = 0.01 : 0.0266 =1: 2.66 = 3:8
So formula U(3)O(8)
Regards :D