The initial concentration of `N_(2)O_(5)` in the following first order reaction:
`N_(2)O_(5)(g) rarr 2NO_(2)(g)+(1)/(2)O_(2)(g)`
was `1.24 xx 10^(-2) mol L^(-1)` at `318 K`. The concentration of `N_(2)O_(5)` after `60 min` was `0.20 xx 10^(-2) mol L^(-1)`. Calculate the rate constant of the reaction at `318 K`.

Options

A. `0.0104" min"^(-1)`
B. `0.0204" min"^(-1)`
C. `0.0304" min"^(-1)`
D. `0.0404" min"^(-1)`

Answer

C

Explanation

For a first order reaction , `"log"([R]_(1))/([R]_(2))=(k(t_(2)-t_(1)))/(2.303)`
`k=(2.303)/((t_(2)-t_(1)))"log"([R]_(1))/[R]_(2)`
`=(2.303)/((60min-0min))"log"(1.24xx10^(-2)"mol "L^(-1))/(0.20xx10^(-2)"mol "L^(-1))` `= (2.303)/(60)log6.2" min"^(-1)=0.0304" min"^(-1)`