Question

Which observation illustrates the law of conservation of mass?

Answer 1

The conservation of mass states that the total mass of reactants present before the reaction occurs is equal to the total mass of products after the reaction. From the choices, the second choice deems fit for the description of the law.

Answer 2

Answer: When 3 g of carbon reacts with 8 g of oxygen, 11 g of carbon dioxide is produced.

Explanation:

According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.

$C+O_2\rightarrow CO_2$

Given: mass of carbon = 3 g

mass of oxygen = 8 g

Mass of products = Mass of carbon dioxide = 11 g

Mass or reactant = mass of carbon + mass of oxygen = 3 g  + 8 g = 11g

Thus the total mass of reactants is equal to the total mass of products.