According to law of mass action rate of a chemical reaction is proportional to

Options

A. Concentration of reactants
B. Concentration of products
C. Product of activemasses of reactant raised to a power equal to their stoichiometry coefficient
D. Molar concentration of products

Answer

To solve the question regarding the law of mass action and its relationship to the rate of a chemical reaction, we can break down the explanation step by step.

### Step-by-Step Solution:

1. **Understanding the Law of Mass Action**:
The law of mass action states that the rate of a chemical reaction at a given temperature is proportional to the product of the active masses (concentrations) of the reacting substances, each raised to the power of their respective stoichiometric coefficients in the balanced chemical equation.

**Hint**: Remember that "active mass" refers to the concentration of the reactants and products in the reaction.

2. **Setting Up the Reaction**:
Consider a general reversible reaction:
\[ aA + bB \rightleftharpoons cC + dD \]
Here, \(A\) and \(B\) are reactants, and \(C\) and \(D\) are products. The letters \(a\), \(b\), \(c\), and \(d\) represent the stoichiometric coefficients.

**Hint**: Identify the reactants and products along with their coefficients in any given reaction.

3. **Writing the Rate Expression**:
According to the law of mass action, the rate of the forward reaction can be expressed as:
\[ \text{Rate} = k \cdot [A]^a \cdot [B]^b \]
where \(k\) is the rate constant, and \([A]\) and \([B]\) are the molar concentrations of the reactants \(A\) and \(B\).

**Hint**: The rate expression involves the concentrations of reactants raised to the power of their coefficients.

4. **Considering the Reverse Reaction**:
For the reverse reaction, the rate can be expressed as:
\[ \text{Rate}_{\text{reverse}} = k' \cdot [C]^c \cdot [D]^d \]
where \(k'\) is the rate constant for the reverse reaction.

**Hint**: The reverse reaction also follows the law of mass action but focuses on the products.

5. **Conclusion**:
Therefore, according to the law of mass action, the rate of a chemical reaction is proportional to the product of the active masses of the reactants raised to the power of their stoichiometric coefficients.

The correct answer to the question is:
\[ \text{Rate} \propto \text{Product of active mass of reactants raised to the power of their stoichiometric coefficients} \]
Thus, the answer is option number C.

### Final Answer:
**The rate of a chemical reaction is proportional to the product of active mass of reactants raised to the power equal to their stoichiometric coefficients.** (Option C)