Question

What is the empirical formula of vanadium oxide , if 2.74 g of the metal oxide contains 1.53 g of metal ?

Answer 1

Mass of Vanadium Oxide = 2.74 grams.

Mass of Vanadium = 1.53 grams.

% comp. of Vanadium = (Mass/Mass of the oxide) × 100%

= (1.53/2.74) × 100%

= 55.84%

% comp. of Oxygen =(100-55.84)%

= 44.16%

Let the mass of compound will be 100 g

So mass of vanadium = 55.84 g

mass of oxygen = 44.16 g

Molar mass of vanadium = 52 g/mol

Molar mass of oxygen = 16 g/mol

Number of moles of vanadium=55.84/52

=1.07

Number of moles of oxygen=44.16/16

=2.7

Lowest number of moles is 1.07 so dividing both atoms moles by it .

V=1.07/1.07

=1

O=2.7/1.07

=2.5

So multiply both by 2 to get a whole number that is:

V=1×2

=2

O=2.5×2

=5

So the formula is V₂O₅.