CBSE Class 10 Answered

Correct answer option is (a) Both (A) and (R) are true, and ® is correct explanation of (A).

Assertion (A): Following is a balanced chemical equation for the action of steam on iron

3Fe + 4H₂O → Fe₃O₄ + 4H₂

Reason (R): The Law of conservation of mass holds good for a chemical equation.

Assertion gives a balanced chemical equation, which has equal number of moles of each element before and after the reaction.

Reason given is law of conservation of mass which states that, "Mass can neither be created nor be destroyed in a chemical reaction. A chemical equation is termed as ‘Balanced chemical equation’, if it has, total mass of elements going under reaction equals total mass of elements after the reaction.”