Question

Which equation satisfies the law of conservation of matter?

A. 3O2 + 2Al  → 2AlO3

B. 4O2 + Al → AlO3

C. 3O2 + Al → 3AlO3

D. 4O2 + 3Al → 4AlO3

Answer 1

The correct answer is A. 3O₂ + 2Al → 2AlO₃

Law of conservation of mass states that mass can nether be created nor destroyed in a closed system or chemical reaction i.e. the total mass of the matter always remains the same throughout the chemical or physical change.

For example, in the given reaction 3O₂ + 2Al → 2AlO₃ the total mass of the reactants is equal to the total mass of the product.

Mass of oxygen = 16 x 3 = 48 AMU

Mass of aluminium = 2 x 27 = 54 AMU

Total molecular mass of the reactants = 102 AMU

Total molecular mass of the product = 2 x 27 + 6 x 8 = 102 AMU.

Hence, the total mass of the matter remains the same.