A reaction is said to be of…………. if its rate is entirely independent of the concentration of the reactants.

Answer

To determine the type of reaction where the rate is entirely independent of the concentration of the reactants, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Reaction Rate**: The rate of a chemical reaction is generally expressed in terms of the concentrations of the reactants. For a reaction involving a reactant A, the rate can be expressed as:
\[ \text{Rate} = k [A]^n \]
where \( k \) is the rate constant, \([A]\) is the concentration of reactant A, and \( n \) is the order of the reaction.

2. **Independence from Concentration**: The question states that the rate is entirely independent of the concentration of the reactants. This implies that changes in the concentration of reactants do not affect the rate of the reaction.

3. **Setting the Order of Reaction**: To achieve a situation where the rate does not depend on the concentration of A, we can set the order \( n \) to zero:
\[ n = 0 \]

4. **Rate Expression for Zero Order**: If \( n = 0 \), the rate expression simplifies to:
\[ \text{Rate} = k [A]^0 \]
Since any quantity raised to the power of zero is equal to one, this simplifies to:
\[ \text{Rate} = k \]
This shows that the rate is constant and does not depend on the concentration of A.

5. **Conclusion**: Therefore, a reaction is said to be of **zero order** if its rate is entirely independent of the concentration of the reactants.

### Final Answer:
A reaction is said to be of **zero order** if its rate is entirely independent of the concentration of the reactants.