Chemical Kinetics

First order gas phase reaction A B + C pi = initial pressure of gas A, pt = total pressure of the reaction mixture at time t Expression of rate constant (k) is

1. 1t pi2pi - pt
2. 1t 2pipi - pt
3. 1t pi3pi - 2pt
4. 1t 3pi4pi - pt

Consider the first order reaction R P. The fraction of molecules decomposed in the given first order reaction can be expressed as

1. 1 - ek1t
2. 1 + ek1t
3. 1 + e-k1t
4. 1 - e-k1t

An organic compound undergoes first order decomposition. The time taken for decomposition to ( 18 )th and ( 110 )th of its initial concentration are t1/8 and t1/10 respectively. What is the value of t1/8 t1/10 10? ( 2 = 0.3)

1. 30
2. 9
3. 3
4. 0.9

Decomposition of A is a first order reaction at T(K) and is given by A(g) B(g) + C(g). In a closed 1 L vessel, 1 bar A(g) is allowed to decompose at T(K). After 100 minutes, the total pressure was 1.5 bar. What is the rate constant (in min-1) of the reaction? ( 2 = 0.3)

1. 6.9 10-4
2. 6.9 10-3
3. 6.9 10-1
4. 6.9 10-2

In a first order decomposition reaction, the time taken for the decomposition of reactant to one fourth and one eighth of its initial concentration are t1 and t2 (s), respectively. The ratio t1/t2 will be:

1. 43
2. 32
3. 34
4. 23

A person's wound was exposed to some bacteria and then bacterial growth started to happen at the same place. The wound was later treated with some antibacterial medicine and the rate of bacterial decay (r) was found to be proportional with the square of the existing number of bacteria at any instance. Which of the following set of graphs correctly represents the 'before' and 'after' situation of the application of the medicine? [Given: N = No. of bacteria, t = time, bacterial growth follows 1st order kinetics.]

1. [figure]
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3. [figure]
4. [figure]

Reaction A(g) 2B(g) + C(g) is a first order reaction. It was started with pure A. array|c|c| t/min & Pressure of system at time t/mm Hg \ 10 & 160 \ & 240 \ array Which of the following option is incorrect?

1. Initial pressure of A is 80 mm Hg
2. The reaction never goes to completion
3. Partial pressure of A after 10 minutes is 40 mm Hg
4. Rate constant of the reaction is 1.693 min-1

A(g) B(g) + C(g) is a first order reaction. array|l|c|c| Time & t & \ Psystem & Pt & P \ array The reaction was started with reactant A only. Which of the following expressions is correct for rate constant k?

1. k = 1t P Pt
2. k = 1t P 2(P - Pt)
3. k = 1t 2(P - Pt)Pt
4. k = 1t P (P - Pt)

For bacterial growth in a cell culture, growth law is very similar to the law of radioactive decay. Which of the following graphs is most suitable to represent bacterial colony growth? Where N - Number of bacteria at any time, N0 - Initial number of bacteria.

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2. [figure]
3. [figure]
4. [figure]

For a reaction, N2O5(g) 2NO2(g) + 12O2(g) in a constant volume container, no products were present initially. The final pressure of the system when 50\% of reaction gets completed is

1. 5/2 times of initial pressure
2. 7/2 times of initial pressure
3. 7/4 times of initial pressure
4. 5 times of initial pressure

Given below are two statements : In the light of the above statements, choose the correct answer from the options given below :

1. Both Statement I and Statement II are false
2. Statement I is true but Statement II is false
3. Statement I is false but Statement II is true
4. Both Statement I and Statement II are true

Integrated rate law equation for a first order gas phase reaction is given by (where Pi is initial pressure and Pt is total pressure at time t)

1. k = 2.303t Pi(2Pi - Pt)
2. k = 2.303t (2Pi - Pt)Pi
3. k = 2.303t Pi(2Pi - Pt)
4. k = 2.303t 2Pi(2Pi - Pt)