Question

Define rate constant (k). write the unit of rate constant for the following :
a) first order reaction
b)second order reaction

Answer 1

The specific rate of reaction when the molar concentration of reacting is taken unity called rate constant
For first order =second inverse
And for second order=Mol inverse litre second inverse

Answer 2

i) Rate constant : It is numerically equals to the rate of reaction when the active mass of each reactant is unity .
that's why it is also known as specific reaction rate .

unit of rate constant for nth order reaction Is given by
lit^n-1 mol^1-n sec^-1

a)so for the first order reaction
put n = 1
we get unit of K Are
sec^-1

b) for second order reaction put n =2
we get the units as
litre mol -¹ sec-¹ .