HARD
JEE Main
IMPORTANT
Earn 100

The formation in water of d-potassium chromo-oxalate from its l-form is a reversible reaction, which is first-order in both directions, the racemate being the equilibrium product. A polarimeter experiment at 22 °C showed that after 560 s, 12 mole % of the l-isomer was converted to the d-form. Find the rate constant for the forward and the reverse reactions.

Given ln0.76=-0.2744

Important Questions on Chemical Kinetics

HARD
JEE Main
IMPORTANT

Derive the equilibrium constant for decomposition of H2O2 from the following data

Time in minute 10 15 20 25
Volume of O2 given by H2O2 6.30 8.95 11.40 13.5 35.75
HARD
JEE Main
IMPORTANT

The kinetics of hydrolysis of methyl acetate in excess dilute HCl at 25 °C were followed by withdrawing 2 mL of the reaction mixture at intervals of (t), adding 50 mL water, and titrating with baryta water. Determine the velocity constant of hydrolysis.

t (in a minute) 0 75 119 259
Titre value (in mL) 19.24 24.20

26.60

32.23 42.03
HARD
JEE Main
IMPORTANT

In the inversion of cane sugar in the presence of an acid, the following polarimeter readings are obtained.

Time (in minute) 0 30 90 230
Rotation (in degree) +46.75 +41.0 +30.75 +12.75 -18.75

Calculate the rate constant.

HARD
JEE Main
IMPORTANT
For a reaction, AB+C, it was found that at the end of 10 minutes from the start, the total optical rotation of the system was 50°and when the reaction is complete, it was 100°. Assuming that only B and C are optically active and dextro-rotatory, calculate the rate constant of this first-order reaction.
HARD
JEE Main
IMPORTANT

For the consecutive unimolecular-type first-order reaction Ak1Rk2S, the concentration of component R CR at any time t is given by
CR=CAOK1e-k1tk2-k1+e-k2tk1-k2

if CA=CAO, CR=CRO=0 at t=0,
The time at which the maximum concentration of R occurs is

EASY
JEE Main
IMPORTANT


In a CSTR, a homogeneous reaction's first-order of the type XYZ (consecutive reaction) is carried out. Among the following, which curve shows a variation of concentration of X, Y and Z with time?

Question Image

HARD
JEE Main
IMPORTANT
For the consecutive unimolecular-type first-order reaction Ak1Rk2S, the concentration of component A, CA at any time t is given by
HARD
JEE Main
IMPORTANT

A substance undergoes a first-order decomposition. The decomposition follows two parallel first-order reactions as given below.

The percentage distributions of B and C are

Question Image

(k1=1.26×10-4 s-1 and k2=3.8×10-5 s-1)