The rate of chemical reaction

Options

A. keeps on increasing with time
B. remains constant with time
C. keeps on decreasing with time
D. shows irregular trend with time.

Explanation

### Step-by-Step Solution

1. **Understanding the Rate of Reaction**: The rate of a chemical reaction refers to how quickly reactants are converted into products. It is typically expressed as the change in concentration of a reactant or product over time.

2. **Rate of Reaction Formula**: The rate of reaction can be mathematically represented as:
\[ \text{Rate} = \frac{d[\text{Reactant}]}{dt} \]
or in a more general form:
\[ \text{Rate} = \frac{\Delta X}{\Delta T} \]
where \( \Delta X \) is the change in concentration and \( \Delta T \) is the change in time.

3. **Effect of Concentration on Rate**: As the reaction proceeds, the concentration of reactants decreases because they are being converted into products. Therefore, the rate of reaction generally decreases over time.

4. **Inversely Proportional Relationship**: The relationship between the rate of reaction and time can be expressed as:
\[ \text{Rate} \propto \frac{1}{t} \]
This indicates that as time (t) increases, the rate of reaction decreases, confirming that the rate is inversely proportional to time.

5. **Conclusion**: Based on the above reasoning, we conclude that the rate of a chemical reaction decreases with time as the concentration of reactants diminishes.

### Final Answer
The rate of a chemical reaction decreases with time.