For a first order reaction,

Options

A. the degree of dissociation is equal to `(1-e^(-kt))`
B. a plot of reciproal concentration of the reactant vs time gives a straight line
C. the time taken for completion of 75 % of reaction is thrice the `t_(1//2)` of the reaction
D. the pre-exoponential factor in the Arrhenius equation has the dimension of time `T^(-1)`

Answer

A, D

Explanation

Degree of dissociation
`=("No. of molecules dissociated")/("Total no. of molecules")`
`=([A]_(0)-[A])/([A]_(0))=([A]_(0)-[A]_(0)e^(-kt))/([A]_(0))`
`=1-e^(-kt)`.