Question

In the Arrhenius for a certain reaction, the value of `A` and `E_(a)` (activation energy) are `4 xx 10^(13) sec^(-1)` and `98.6 "kJ mol"^(-1)`, respectively. If the reaction is of first order, the temperature at which its half-life period is `10` minutes is
A. `280 K`
B. `290 K`
C. `311.35 K`
D. `418.26 K`

Answer 1

Correct Answer - C
Calculation of `k`:
We know that `k = (2.303)/(t) "log"((a)/(a-x))`
`(t_(1//2)=10xx60 sec)=1.1558xx10^(-3)`
According to Arrehenius equation,
`log k = log A - (Ea)/(2.303 RT)`
Substituting the various values in the above equation
`log 1.155 xx 10^(-3) = log 4 xx 10^(13) - (98.6)/(2.303 xx 8.314 xx 10^(-3) xx T)`
On usual calculation, `T = 311.35 K`