Combustion problem??

Question

Please help me!! Just 61.2 mg of vanadium metal, V, is burned in air to yield 109.2 mg of an oxide. Calculate the simplest formula of this oxide.

Answer 1

I would be happy to set you on fire

Answer 2

Mass O = 109.2 - 61.2 = 48 mg

Moles O = 0.048 g/ 16 g/mol =0.003

Moles V = 0.0612 g / 50.9415 g/mol =0.00120

0.003/ 0.00120 = 2.5 => O

0.00120 / 0.00120 = 1 => V

to get whole numbers we multiply by 2

V2O5 is the formula