Question

The mass of a piece of wood before and after burning was checked and found to be very different. Do you think it follows the law of conservation of mass? How?

Answer 1

• Law of conservation of mass states that - ‘Mass can neither be created nor be destroyed. It can only be transformed from one form to another.’
• When a piece of wood is burnt the following reaction takes place.
• $\mathrm{Wood}+\mathrm{Oxygen}\to \mathrm{Carbon}\mathrm{dioxide}+\mathrm{Water}+\mathrm{Ash}$
• Now the weight of the wood after burning is different from the weight of the wood before burning because Carbon dioxide and water are also formed as by-products which balance the weight of the product with the weight of the reactants.
• Hence, the above reaction follows the law of conservation of mass.