A certain amount of methyl acetate was hydrolysed in the presence of excess of "0.05 M HCl at "25^(@)C. 20 mL of reaction mixture were removed and titrated with NaOH solution, the volume V of alkali required for neutralisation after time ‘t’ were as follows : {:("t(min)",0,20,40,60,oo),("v(mL)",20.2,25.6,29.5,32.8,50.5):} Show that the reaction is the first order reaction.

A certain amount of methyl acetate was hydrolysed in the presence of e

1.	A certain amount of methyl acetate was hydrolysed in the presence of excess of "0.05 M HCl at "25^(@)C. 20 mL of reaction mixture were removed and titrated with NaOH solution, the volume V of alkali required for neutralisation after time ‘t’ were as follows : {:("t(min)",0,20,40,60,oo),("v(mL)",20.2,25.6,29.5,32.8,50.5):} Show that the reaction is the first order reaction.
Answer» Solution :`K=(2.303)/(t)log""((V_(oo)-V_(o))/((V_(oo)-V_(t))))` `V_(oo)-V_(o)=50.4-20.2=30.2` When `t="20 MTS. "k=(2.303)/(20)log""(50.4-20.2)/(50.4-25.6)` `=0.1151 log""(30.2)/(24.8)` `=0.1151 log 1.2479` `=01151 xx 0.0959 =11.03xx10^(-3)" MIN"^(-1)` when t=40 mts `k=(2.303)/(40)log""(50.4-20.2)/(50.2-29.5)` `=0.0576xxlog""(30.2)/(20.9)=0.0576xx0.1596` `=9.19xx10^(-3)" min"^(-1)` `" when"t="60 mts"` `k=(2.303)/(60)log""(50.4-20.2)/(50.2-32.8)=0.03838xxlog""(30.2)/(17.6)` `=0.03838xx0.2343=8.99xx10^(-3)" min"^(-1)` The constant values of k show that the reaction is of FIRST order.