Calculate the percent composition of the following:

A. VO3

B. V2O5

A) Answer is: 51.48% V and 48.52% O.

Ar (V) = 50.94; atomic weight of vanadium.

Ar (O) = 16; atomic weight of oxygen.

Ar (VO₃) = 50.94 + 3 · 16.

Ar (VO₃) = 98.94; molecular weight of vanadium (VI) oxide.

ω (V) = Ar (V) : Ar (VO₃) · 100%.

ω (V) = 51.48%; the percent composition of vanadium.

ω (O) = 100% - 51.48%.

ω (O) = 48.52%; the percent composition of oxygen.

B) Answer is: 67.80% V and 32.20% O.

Ar (V) = 50.94; atomic weight of vanadium.

Ar (O) = 16; atomic weight of oxygen.

Ar (V₂O₅) = 2 · 50.94 + 5 · 16.

Ar (V₂O₅) = 149.88; molecular weight of vanadium (V) oxide.

ω (V) = 2 · Ar (V) : Ar (V₂O₅) · 100%.

ω (V) = 67.80%; the percent composition of vanadium.

ω (O) = 100% - 67.80%.

ω (O) = 32.20%; the percent composition of oxygen.