Advertisements
Advertisements
प्रश्न
A first-order reaction is 50% complete in 30 minutes at 300 K and in 10 minutes at 320 K. Calculate activation energy (Ea) for the reaction. [R = 8.314 J K−1 mol−1]
[Given: log 2 = 0.3010, log 3 = 0.4771, log 4 = 0.6021]
A first order reaction is 50% completed in 30 minutes at 300 K and in 10 minutes at 320 K. Calculate the activation energy of the reaction. (R = 8.314 J K−1 mol−1)
Advertisements
उत्तर
Given: T1/2 = 30 min, T1 = 300 K
T1/2 = 10 min, T2 = 320 K
Formula: `log k_2/k_1 = E_a/(2.303 R) [1/T_1 - 1/T_2]`
k = `0.693/(t_(1//2))`
k1 at 300 K = `0.693/30` min−1
k2 at 320 K = `0.693/10` min−1
`log (k_2/k_1) = E_a/(2.303 R) [1/T_1 - 1/T_2]`
`log ((0.693/10)/(0.693/30)) = E_a/(2.303 R) [1/300 - 1/320]`
log (3) = `E_a/(2.303 R) [20/(300 xx 320)]`
0.4771 = `E_a/(2.303 xx 8.314) [20/(96000)]`
0.4771 = `E_a/(2.303 xx 8.314) [20/(96000)]`
Ea = `(0.4771 xx 2.303 xx 8.314 xx 96000)/20`
= `876969.73/20`
= 43848.48 J/mol
Ea = 43.8 kJ mol−1
Hence, the activation energy of the reaction is 43.8 kJ−1.
APPEARS IN
संबंधित प्रश्न
The rate constant for the first-order decomposition of H2O2 is given by the following equation:
`logk=14.2-(1.0xx10^4)/TK`
Calculate Ea for this reaction and rate constant k if its half-life period be 200 minutes.
(Given: R = 8.314 JK–1 mol–1)
The rate constant of a first order reaction are 0.58 S-1 at 313 K and 0.045 S-1 at 293 K. What is the energy of activation for the reaction?
Explain the following terms :
Half life period of a reaction (t1/2)
The rate of chemical reaction becomes double for every 10° rise in temperature because of ____________.
Consider figure and mark the correct option.
Which of the following statements are in accordance with the Arrhenius equation?
(i) Rate of a reaction increases with increase in temperature.
(ii) Rate of a reaction increases with decrease in activation energy.
(iii) Rate constant decreases exponentially with increase in temperature.
(iv) Rate of reaction decreases with decrease in activation energy.
The activation energy in a chemical reaction is defined as ______.
The activation energy of one of the reactions in a biochemical process is 532611 J mol–1. When the temperature falls from 310 K to 300 K, the change in rate constant observed is k300 = x × 10–3 k310. The value of x is ______.
[Given: ln 10 = 2.3, R = 8.3 J K–1 mol–1]
A schematic plot of ln Keq versus inverse of temperature for a reaction is shown below

The reaction must be:
It is generally observed that the rate of a chemical reaction becomes double with every 10°C rise in temperature. If the generalisation holds true for a reaction in the temperature range of 298 K to 308 K, what would be the value of activation energy (Ea) for the reaction?
