Chemical Kinetics & Thermodynamics (26-12-2017) - IIT JAM MCQ

For the reaction shown below,

The value of k₁ is 1 × 10^–4 s^–1. If the reaction starts from X, the ratio of the concentrations of Y and Z at any given time during the course of the reaction is found to be The value of k₂ is:

For a first order gas phase reaction,

P₀ be initial pressure of A and P_t be the total pressure at time ‘t’. Integrated rate equation is:

The value of the rate constant for the gas phase reaction,   is 38 dm³ mol^–1 s^–1 at 300 K. The order of the reaction is:

A reaction follows second order rate law,  

The specific rate constant of decomposition of a compound is represented by

  The activation energy of decomposition for this compound at 300 K is:

The fluorescence life time of a molecule in solution is 10 ns. If the fluorescence quantum yield is 0.1, the rate constant of fluorescence decay is:

For the reaction, P + Q + R → S, experiment data for the measured initial rates is given below:

The order of the reaction with respect to P, Q and R respectively, is:

Sucrose is converted to a mixture of glucose and fructose in a pseudo first order process under alkaline conditions. The reaction has a half-life of 28.4 min. The time required for the reduction of a 8.0 mM sample of sucrose to 1.0 mM is:

The reaction, proceeds via the following steps:

The rate of this reaction is equal to

1 g of ⁹⁰Sr gets converted to 0.953 g after 2 yr. The half-life of ⁹⁰Sr, and the amount of ⁹⁰Sr remaining after 5 yr are:

Consider an exothermic reaction

As the temperature increases

A reaction proceeds through the formation of an intermediate B in a unimolecular reaction

The integrated rate law for this reaction is:

If k_a >> k_b, then concentration versus time plot for the reaction is:

Noncatalytic oxidation of the aromatic hydrocarbons is slow at which temperature?

The half-life of a first order reaction varies with temperature according to:

The molar entropy of crystalline CO at absolute zero is:

Among the following, the system that would require the least amount of thermal energy to bring its temperature to 80°C is:

The plot that describes a Carnot cycle is:

The rate of evaporation of a liquid is always faster at a higher temperature because:

For the process,

1 Ar (300 K, 1 bar) → 1Ar (200 K, 10 bar) assuming ideal gas behaviour, the change in molar entropy is:

For the reaction,

Compute the entropy change (in J/K/mol) for the process and comment on the sign of the property.

For the reaction,

The thermodynamic properties

A radioactive isotope having a half-life of 3 days was received after 12 days. It was found that there were 3 g of the isotope in the container. The initial weight of the isotope when packed was:

Among the following, the most stable isotope to radioactive decay is:

Activity of a radioactive substance is A₁ at time t₁ and A₂ at time t₂ (t₂ > t₁). The activity ratio is

(λ = decay constant)

A radioactive sample consists of two distinct species having equal number of atoms initially. The mean life of one species is t and that of the other is 5t. The decay products in both cases are stable. A plot is made of the total number of radioactive nuclei as a function of time. What of the following figures best represents the form of this plot: