Question

Drive the expression for rate constant of 2nd oder reation (assuming the initial Consta are to be Same). Also determine the unit for k and half life period for second order reaction.​

Answer 1

The rate constant(k) of first order reaction is k=

t

1

ln

(a−x)

α

where a is moles per litre of the reactant initially and after time t suppose x moles per litre of it is decomposed.

Half-life(t

1/2

) is defined as the time taken for the quantity to reduce to its half value.

Here x=

2

a

, thus from the above equation.

t

1/2

=

k

1

ln

(a−

2

a

)

a

=

k

1

ln

a

2a

=

k

1

l

n

2

t

1/2

=

k

l

n

2

=

k

0.693

t

1/2

=

k

0.693

.