NEET Chemistry Chemical Kinetics Questions Solved


The following data were obtained during the first order thermal decomposition of SO2Cl2 at a constant volume.

SO2Cl2 (g) SO2 (g) + Cl2 (g)

Experiment          Time/s            Total pressure/atm
1                           0                         0.5
2                        100                        0.6

Calculate the rate of the reaction when total pressure is 0.65 atm.

(A) 7.8 × 10-4 s-1 atm.                                   (B) 0.8 × 10-4 s-1 atm.

(C) 2.4 × 10-2 s-1 atm.                                   (D) 6.1 × 10-8 s-1 atm.

(A). If the reaction is assumed to proceed to completion, the final pressure will be doubled the initial pressure. Then for a first order reaction, one can write.

k=2.303tlogpf-pipf-pi=2.303tlog1-0.5atm1-0.6atmFor t=100 sk=2.303tlog0.5 atm0.4 atm=2.23×10-3s-1

For total pressure of 0.65 atm,

Rate the reaction= kp (SO2Cl2 )

From the reaction stoichiometry,

p(SO2Cl2 ) = 2pi  pt = 1 atm  0.65 atm = 0.35 atm 

So, Rate of reaction = 2.23 × 10-3 s-1 × 0.35 atm

                               = 7.8 × 10-4 s-1 atm.

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