Define the following terms :
(i) Pseudo first order reactions
(ii) Half life period of reaction `(t_(1//2))`.

Explanation

(i) Pseudo first-oder reaction : Pseudo first-order reaction the reaction which in bimolecular
but whose order is one is one is called pseudo first-order reaction. This happens when one of
the reaction is present in large amount . For example, in acidic hydrolysis of ester
(ethylacetate), water is present in a large quantily.
`CH_(3)COOC_(2)+H_(2)OtoCH_(3)COOH+C_(2)H_(5)OH`
similarly inversion of cane sugar or hydrolysis of cane suger in an example of pseudo first order reasction .
(ii) Half-life period of a reaction : Half-life period of a reaction s the time taken for half of the
reaction to be completed . In other words, the time in which the concentration of a reactant
is reduced o half of its original value is called half-life period of the reaction .
For first-order reaction `t_(1//2)=(0.693)/(k)`