IIT JEE , AIEEE Forum - Chemistry , Physical Chemistry

mastermind890

The inversion of cane sugar proceeds with a half life of 600 minutes at pH=5 for any concentration of sugar.However if pH=6,the half life changes to 60 minute.The rate law expression for sugar inverion can be written as
(A) r=k.[sugar]²[H⁺]⁰
(B)r=k.[sugar]¹[H⁺]⁰(C)r=k.[sugar]¹[H⁺]¹(D)r=k.[sugar]⁰[H⁺]¹

sandeepramesh

must be c i think

bsgdabest

edited

elastiboysai

supralara

doe snt depend on sugar conc

so answer of sairam is right

sandeepramesh

sorry i didnt notice this:

for any concentration of sugar

so its D

mastermind890

it must be d
but the ans given is c

ramkumar_november

Let T denote half life........

T = K [H⁺]^(1-n)

when pH = 5 [H⁺] = 10^-5

600 = K 10^-5(1-n) .........(1)

when pH = 6 [H⁺] = 10^-6

60 = K 10^-6(1-n) ..............(2)

(1) divided by (2) ..... we get

10 = 10^-5+5n+6-6n

1-n = 1

so n=0

thus (B) is the right option.........

rate = k[sugar]¹[H⁺]⁰

mastermind890

@ ramkumar
it is given that The inversion of cane sugar proceeds with a half life of 600 minutes at pH=5 for "any concentration of sugar."
so how can it be (B)????

dev_22oct

ans is b.

becoz the half life is not changing with conc...t _1/2 =[conc]⁰ so its first order withrespect to sugar.