Concentration of a reactant A is changed from 0.044 M to 0.032 M in 25 minutes, the average rate of the reaction during this interval is

Options

A. 0.0048 mole/lit/min
B. 0.00048 mole/lit/sec
C. `4.8xx10^(-4)` mole/lit/min
D. 0.0048 mole/lit/sec

Answer

To find the average rate of the reaction when the concentration of reactant A changes from 0.044 M to 0.032 M over a period of 25 minutes, we can follow these steps:

### Step 1: Determine the change in concentration (ΔC)
The change in concentration (ΔC) can be calculated using the formula:
\[ \Delta C = C_{\text{final}} - C_{\text{initial}} \]
Where:
- \(C_{\text{final}} = 0.032 \, \text{M}\)
- \(C_{\text{initial}} = 0.044 \, \text{M}\)

Substituting the values:
\[ \Delta C = 0.032 \, \text{M} - 0.044 \, \text{M} = -0.012 \, \text{M} \]

### Step 2: Determine the change in time (Δt)
The change in time (Δt) is given as:
\[ \Delta t = 25 \, \text{minutes} \]

### Step 3: Calculate the average rate of reaction
The average rate of reaction can be calculated using the formula:
\[ \text{Average Rate} = \frac{\Delta C}{\Delta t} \]
Substituting the values:
\[ \text{Average Rate} = \frac{-0.012 \, \text{M}}{25 \, \text{minutes}} \]

Calculating this gives:
\[ \text{Average Rate} = -0.00048 \, \text{M/min} \]

### Step 4: Convert the rate to M/s
To convert the rate from M/min to M/s, we can use the conversion factor:
\[ 1 \, \text{minute} = 60 \, \text{seconds} \]
Thus:
\[ \text{Average Rate} = -0.00048 \, \text{M/min} \times \frac{1 \, \text{min}}{60 \, \text{s}} = -0.000008 \, \text{M/s} = -4.8 \times 10^{-4} \, \text{M/s} \]

### Final Result
The average rate of the reaction is:
\[ \text{Average Rate} = 4.8 \times 10^{-4} \, \text{M/min} \text{ or } 0.00048 \, \text{M/s} \]