Question

Verify law of conservation of mass for the below equation:
Mg + O2n= MgO

Answer 1

The atomic masses:

Magnesium (Mg) = 24 amu

Oxygen (O) = 16 amu

LHS of equation:

Mass of reactants = 24 + 2(16) = 56 amu

RHS of equation:

Mass of product = 24 + 16 = 40 amu

Thus, the equation:

$\sf { Mg + O_{2} → MgO }$

is incorrect.

The balanced equation should be:

$\bold {\sf { 2Mg + O_{2} → 2MgO }}$

In this equation;

Mass of reactants = Mass of product = 80 amu

Hence, we balance equations in order to obey the Law of Conservation of Mass.