Chemical Kinetics Test (20-12-2016) - IIT JAM MCQ

Two different first order reaction have rate constant K₁ and K₂ at T₁ (k₁ > k₂). If temperature is increased from T₁ to T₂, then new constants become K₃ to K₄ respectively: which among the following relation is correct?        

The decomposition of N_­2O₅ according to the equation,

 N₂O_5(g) → 4NO_2(g) + O_2(g)

 Is a first order reaction. After 30 minutes from the start of the decomposition in a closed vessel, the total pressure developed is found to be  284.4 mmHg and on completion, the total pressure is 584.5 mmHg. Calculate the Rate constant of the reaction.

The addition of a catalyst to the reaction system

A monoatomic gas, X, adsorbed on a surface, follows Langmuir adsoption isotherm. A plot of  the fraction of surface coverage, θ, against the concentration of the gas [X], for very low concentration fo the gas is described by the equation

Following graphs willbe true when : 

Ozone depletion take place as:

Order of Rxⁿ will be:

Chemical reaction occurs as a result of collisions between reacting molecules. Therefore, the reaction rate is given by: 

         Which of the following factors are responsible for the increase in the rate of a surface catalysed reaction?

(I) A catalyst provides proper orientation for the reactant molecules to react.

(II) Heat of adsorption of reactants on a catalyst helps reactant molecules to overcome activation energy.

(III) The catalyst increases the activation energy of the reaction.

(IV) Adsorption increases the local concentration of reactant molecules on the surface of the catalyst.

 Select the correct answer using the codes given below:

A graph between log t_1/2 and log a (abscissa), a being the initial concentration of A in the reaction for reaction A → product, the rate law is:

In a zero-order reaction for every 10° rise of temperature, the rate is doubled. If the temperature is increased from 10°C to 100°C, the rate of the reaction will become 

The value  for n^th order reaction is:

A reaction rate constant is given by :  It means:

Consider the following statements, which statements is / are correct

Which of the following is correct statement:

       For the reaction of first order

The observed rate of a chemical reaction is substantially lower than the collision frequency. One or more of the following statements is/are true to account for this fact:  

Which of the following graphs are correct?

The reaction A(g) + 2B(g) → C(g) is an elementary reaction. In an experiment involving this reaction, the initial partial pressure of A and B are P_A = 0.40 atm and P_B = 1.0 atm respectively. When P_C = 0.3 atm, the rate of the reaction relative to the initial rate is:

A certain zeroth order reaction has k = 0.025 M s-1 for the disappearance of A. what will be the concentration of A after 15s if the initial concentration is 0.50 M?

For a first order reaction, A→product, the rate of reaction at (A) = 0.2 mol^-1 is 1.0 × 10^-2 mol L^-1 min^-1 the half life period for the reaction is :

In a chemical reaction two reactants take part. The rate of reaction is directly proportional to the concentration of one of them and inversely proportional to the concentration of the other. The order of the reaction is

The activation energy of a certain reaction is 87 kJ mol^-1. What is the ratio of the rate constants for theis reaction when the temperature is decreased from 37⁰C to 15⁰C ?

In hydrogenation reaction at 25°C, it is observed that hydrogen gas pressure falls from 2 atm to 1.2 atm in 50 min. Calculate the rate of reaction in molarity per sec (in term 10^-5). (R = 0.0821 litre–atm degree^-1 mol^-1)

A catalyst

Calculate the rate constants involved in the dissociation of NH₄OH , vis., 

from the following data : A 0.01 molar solution of NH₄OH is subjected to a sudden temperature jump terminating at 25°C, at which temperature, the equilibrium constant is 1.8 × 10^–5 mol dm^–3. The observed relaxation time is 0.109 μs and x_e = 4.1 × 10^–4 mol dm^–3. (in 10¹⁰ dm³ mol^–1 s^–1) 

A substance when dissolved in water at 10^–3 M concentration absorbs 10 per cent of an incident radiation in a path of 1 cm length.The concentration of the solution in order to absorb 90 per cent of the same radiation is: x × 10^–2 what will be value of x : 

An 18°C, the surface tension γ of an aqueous solution of butyric acid is represented by the equation γ = γ₀ – 29.8 log (19.64 c₂ + 1) where γ₀, the surface tension of water, is 0.073 N m^–1 and c₂ is the bulk concentration of the solute. Calculated, using the Gibbs adsorbtion isotherm, the surface excess of butyric acid at concentration c₂ equal to 0.01 mol dm^–3 is 8.8 × 10^–x mol m^–2 what will be value of x: