Why the law of conservation of mass requires chemical equations to be balanced?

 The law of conservation of mass states that the mass cannot be created or destroyed in a chemical reaction.

The total mass of the reactants in a chemical reaction must be equal to the total mass of products.

The total mass of the system remains the same before and after a chemical reaction.

A chemical equation is a symbolic representation of a chemical equation in which atoms of reactants and products are written.

Atoms of reactants get converted into products, so in a chemical equation number of atoms on both sides must be the same or equal.

We can understand it with an example

  `CH_4 + O_2 → CO_2 + H_2O`

The total mass of reactants = 44g

Total mass of products = 62g

This is an unbalanced equation in which the total mass of the reactant is 44g  and the total mass of the product is 62 g, so this situation does not satisfy the law of conservation of mass.

  `CH_4 + 2O_2 → CO_2 + 2H_2O`

The total mass of reactants = 80 g

Total mass of products = 80 g

This is a balanced equation in which the number of atoms on both sides is equal that’s why the total mass of reactants is equal to the total mass of the product.

That’s why the law of conservation of mass requires chemical equations to be balanced.

Related Topics

1. Formation of Sodium ion

2. Formation of chloride ion

3. Chemical Properties of Metals

4. Physical Properties of Metals

FAQs 

1. Which postulate of Dalton’s atomic theory is the result of the law of conservation of mass?

Ans – Chemical reactions involve the reorganization of atoms. These are neither created nor destroyed in a chemical reaction.

2. Limitations of law of conservation of mass

Ans  – The law of conservation of mass is not applicable to nuclear reactions i.e., nuclear fusion and nuclear fission.

3. Who gave the law of conservation of mass?

Ans – Antonio Lavoisier