Answer:
V2O5 is the empirical formula of vanadium oxide
Step-by-step explanation:
The molecular mass of Vanadium is 50.949 g/mol 
Number of moles of vanadium = 0.3456 g/50.949 g/mol = 0.00696 moles 
The molecular mass of Oxygen is 16.0 g/mol 
Number of moles of Oxygen = (0.6330 – 0.354) g/16 g/mol = 0.0174 moles 
Emperical formula 
V (0.00696 moles/0.00696 moles) O (0.0174 moles /0.00696 moles) 
V 1 O2.5 
Multiply by two get a whole number 
V2 O5