Visit the website 123iitjee.manishverma.site for latest posts, courses, admission & more.

### JEE Advanced 2013 Chemistry Chemical Kinetics Solution

Problem

In the reaction,

the time taken for 75% reaction of P is twice the time taken for 50% reaction of P. The concentration of Q varies with reaction time as shown in the figure. The overall order of the reaction is

(A) 2                                                         (B) 3
(C) 0                                                         (D) 1

Solution

Since, the order does not depend on [Q]. Clearly, the reaction is zero order w.r.t. Q.

For first order reaction it takes one half life for 50% completion and two half lives for 75% completion. Clearly, the reaction is first order w.r.t. P.

Hence, overall order = 0 +1 = 1 (D).

### Sum of the coefficients in the expansion of $(x+y)^n$ ....

If the sum of the coefficients in the expansion of $(x+y)^n$ is 4096, then the greatest coefficient in the expansion is _ _ _ _ . Solution $C_0 + C_1 + C_2 + C_3 + ......................... + C_n =4096$ $\therefore 2^n = 4096 =2^{12}$ $\Rightarrow n = 12$ Greatest coefficient = ${}^{12}{C_6} = 924$