The ratio of the rate constant of a reaction at two temperatures diffe...
Explanation: Half-life period of a first order reaction is directly proportional to the rate constant. So, it increases with increase in temperature.
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The ratio of the rate constant of a reaction at two temperatures diffe...
For every 10° C rise in temp, the reaction becomes twice i.e 2× the initial rate( and sometimes even thrice).
The ratio of the rate constant at the initial temperature and the temp 10°C higher is the temp. coeff. of the reaction.
The ratio of the rate constant of a reaction at two temperatures diffe...
The temperature coefficient of a reaction is a measure of how the rate constant of a reaction changes with temperature. It is expressed as the ratio of the rate constant at two temperatures differing by a specific temperature interval. In this case, the temperature interval is 10°C.
To calculate the temperature coefficient of a reaction, we use the Arrhenius equation:
k = A * e^(-Ea/RT)
Where:
- k is the rate constant
- A is the pre-exponential factor (also known as the frequency factor)
- Ea is the activation energy
- R is the ideal gas constant
- T is the temperature in Kelvin
Now, let's consider two temperatures, T1 and T2, differing by 10°C. The ratio of the rate constants at these temperatures can be denoted as:
k2/k1 = (A * e^(-Ea/RT2))/(A * e^(-Ea/RT1))
Since the pre-exponential factor cancels out, we can simplify the equation to:
k2/k1 = e^(-Ea/R) * e^(Ea/T1) * e^(-Ea/T2)
Now, let's take the natural logarithm of both sides to eliminate the exponential terms:
ln(k2/k1) = -Ea/R * (1/T2 - 1/T1)
We can rewrite this equation as:
ln(k2/k1) = -Ea/R * (T1 - T2)/(T1 * T2)
Now, let's rearrange the equation to solve for the temperature coefficient:
k2/k1 = e^(-Ea/R * (T1 - T2)/(T1 * T2))
The temperature coefficient is given by the ratio of the rate constants, so:
Temperature coefficient = k2/k1 = e^(-Ea/R * (T1 - T2)/(T1 * T2))
Since the temperature interval in this case is 10°C, the correct answer is option 'B' (10).