What is the unit of rate of chemical reaction ?

Answer

To determine the unit of the rate of a chemical reaction, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Rate of Reaction**:
The rate of a chemical reaction is defined as the change in concentration of reactants or products over a specific period of time.

2. **Expression for Rate**:
Mathematically, the rate of reaction can be expressed as:
\[ \text{Rate} = \frac{\Delta [\text{Concentration}]}{\Delta t} \]
where \(\Delta [\text{Concentration}]\) represents the change in concentration and \(\Delta t\) represents the change in time.

3. **Units of Concentration**:
Concentration is typically measured in moles per liter (mol/L), which is also referred to as molarity (M).

4. **Unit of Time**:
The unit of time is usually in seconds (s).

5. **Combining Units**:
Therefore, the unit of rate of reaction can be expressed as:
\[ \text{Rate} = \frac{\text{mol/L}}{\text{s}} = \frac{\text{mol}}{\text{L} \cdot \text{s}} \]

6. **Alternative Representation**:
The unit of liter can also be expressed in cubic meters (m³), hence:
\[ \text{L} = \text{m}^3 \]
This gives us an alternative expression for the unit of rate:
\[ \text{Rate} = \frac{\text{mol}}{\text{m}^3 \cdot \text{s}} = \text{mol} \cdot \text{m}^{-3} \cdot \text{s}^{-1} \]

7. **Final Answer**:
Thus, the unit of the rate of a chemical reaction can be summarized as:
\[ \text{mol} \cdot \text{L}^{-1} \cdot \text{s}^{-1} \quad \text{or} \quad \text{mol} \cdot \text{m}^{-3} \cdot \text{s}^{-1} \]

### Final Answer:
The unit of the rate of a chemical reaction is \( \text{mol} \cdot \text{L}^{-1} \cdot \text{s}^{-1} \) or \( \text{mol} \cdot \text{m}^{-3} \cdot \text{s}^{-1} \).

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