Question

Which of the following equation satisfies the law of conservation of mass?

• A. C + O${}_2$ → CO${}_2$
• B. 2C + O${}_2$ → CO${}_2$
• C. 4C + O${}_2$ → CO${}_2$
• D. C + 2O${}_2$ → CO${}_2$

Answer 1

The correct option is A C + O${}_2$ → CO${}_2$

According to the law of conservation of mass, the total mass of the elements present in the reactants is equal to the total mass of the elements present in the products of a chemical reaction.

C + O${}_2$ → CO${}_2$
Total mass of reactants = 12 + 32 = 44
Total mass of products = 12 + 32 = 44

The total mass of reactants is not equal to the total mass of products for the rest of the given reactions. Thus, the law of conservation of mass is not obeyed.