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For a chemical reaction at 27^(@)C, the ...

For a chemical reaction at `27^(@)C`, the activation energy is 600R. The ratio of the rate constants at `327^(@)C` to that of at `27^(@)C` will be

A

2

B

40

C

e

D

`e^(2)`

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The correct Answer is:
To solve the problem of finding the ratio of the rate constants \( K_2 \) at \( 327^\circ C \) to \( K_1 \) at \( 27^\circ C \), we will use the Arrhenius equation. The Arrhenius equation relates the rate constant \( K \) to the temperature \( T \) and the activation energy \( E_a \): \[ K = A e^{-\frac{E_a}{RT}} \] Where: - \( K \) is the rate constant, - \( A \) is the pre-exponential factor, - \( E_a \) is the activation energy, - \( R \) is the universal gas constant, - \( T \) is the absolute temperature in Kelvin. ### Step 1: Convert temperatures to Kelvin First, we need to convert the given temperatures from Celsius to Kelvin. - For \( T_1 = 27^\circ C \): \[ T_1 = 27 + 273 = 300 \, K \] - For \( T_2 = 327^\circ C \): \[ T_2 = 327 + 273 = 600 \, K \] ### Step 2: Write the Arrhenius equation for both temperatures Using the Arrhenius equation, we can express the rate constants at both temperatures: \[ K_1 = A e^{-\frac{E_a}{RT_1}} \quad \text{and} \quad K_2 = A e^{-\frac{E_a}{RT_2}} \] ### Step 3: Find the ratio of rate constants To find the ratio \( \frac{K_2}{K_1} \): \[ \frac{K_2}{K_1} = \frac{A e^{-\frac{E_a}{RT_2}}}{A e^{-\frac{E_a}{RT_1}}} \] The \( A \) cancels out: \[ \frac{K_2}{K_1} = e^{-\frac{E_a}{RT_2} + \frac{E_a}{RT_1}} = e^{E_a \left( \frac{1}{RT_1} - \frac{1}{RT_2} \right)} \] ### Step 4: Substitute the values Given \( E_a = 600R \): \[ \frac{K_2}{K_1} = e^{600R \left( \frac{1}{R \cdot 300} - \frac{1}{R \cdot 600} \right)} \] This simplifies to: \[ \frac{K_2}{K_1} = e^{600 \left( \frac{1}{300} - \frac{1}{600} \right)} \] Calculating the expression inside the exponent: \[ \frac{1}{300} - \frac{1}{600} = \frac{2 - 1}{600} = \frac{1}{600} \] Thus, we have: \[ \frac{K_2}{K_1} = e^{600 \cdot \frac{1}{600}} = e^1 = e \] ### Final Answer The ratio of the rate constants at \( 327^\circ C \) to that at \( 27^\circ C \) is: \[ \frac{K_2}{K_1} = e \]

To solve the problem of finding the ratio of the rate constants \( K_2 \) at \( 327^\circ C \) to \( K_1 \) at \( 27^\circ C \), we will use the Arrhenius equation. The Arrhenius equation relates the rate constant \( K \) to the temperature \( T \) and the activation energy \( E_a \): \[ K = A e^{-\frac{E_a}{RT}} \] Where: - \( K \) is the rate constant, ...
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