NTA Abhyas NEET2020ChemistryChemical KineticsPractice
Which is correct for a first order reaction
Options
- AThe degree of dissociation is equal to ( 1 - e - k t )
- BA plot of reciprocal concentration of the reactant vs time gives a straight line
- CThe time taken for the completion of 75% reaction is thrice the t 1 / 2 of the reaction
- DThe pre-exponential factor in the Arrhenius equation has the dimension of time T - 2
Correct answer
A. The degree of dissociation is equal to ( 1 - e - k t )
Step-by-step solution
( A ) is correct because degree of dissociation = 1 - e - k t at any time t. ( B ) is wrong because plot of log [A] vs t is a straight line ( C ) is wrong because time taken for 75% reaction is two half life. ( D ) is wrong because in k = A e - E a / R T , E a / R T is dimensionless hence A has the unit of K .