Correct Option
The correct option is Both A and R are true but R is NOT the correct explanation of A
Explanation
A skeletal chemical equation represents the chemical formulas of reactants and products without indicating their relative quantities. It is essentially an unbalanced equation. The fundamental principle governing chemical reactions is the Law of Conservation of Mass.
Statement-wise Analysis
- Assertion (A): Correct. Skeletal equations must be balanced to satisfy the Law of Conservation of Mass, which states that matter can neither be created nor destroyed in a chemical reaction. Consequently, the number of atoms of each element must be the same on both the reactant and product sides. Quantitative calculations (stoichiometry) rely on accurate mole ratios, which are only available in a balanced equation.
- Reason (R): Correct. Chemical equations provide specific information regarding the physical states of the substances involved. Notations such as (g) for gas, (l) for liquid, (s) for solid, and (aq) for aqueous solution are used to make the equation more informative.
- Relationship: While both statements are individually true, the information regarding physical states (Reason) does not explain why an equation must be balanced. The necessity for balancing arises strictly from the conservation of mass, not from the notation of physical states. Therefore, R is not the correct explanation for A.
Key Takeaway: Chemical equations are balanced to ensure that the total mass of the reactants equals the total mass of the products, in strict adherence to the Law of Conservation of Mass.