Chemical Kineti...

The rate of a reaction is expressed in different ways as follows :

 = 

The reaction is :

The rate constant for the forward reaction A(g)  2B(g) is 1.5 × 10^-3 s^-1 at 100 K. If 10^-5 moles of A and 100 moles of B are present in a 10 litre vessel at equilibrium then rate constant for the backward reaction at this temperature is

Reaction A + B → C + D follow's following rate law : rate = k[A]^+1/2[B]^1/2. Starting with initial conc. of 1 M of A and B each, what is the time taken for concentration of A of become 0.25 M.

Given : k = 2.303 × 10^-3 sec^-1.

Consider the following first order competing reactions :

X  A+ B      and y  C+D

if 50% of the reaction of X was completed when 96% of the reaction of Y was completed, the ratio of their rate constants   is

Units of rate constant for first and zero order reactions in terms of molarity (M) are respectively.

The rate of a chemical reaction doubles for every 10°C rise of temperature. If the temperature is raised by 50°C, the rate of the reaction increases by about

For a reaction pA + qB → products, the rate law expression is r = k[A]^l[B]^m, then :

In the reaction : A + 2B → 3C + D, which of the following expression does not describe changes in the conc. of various species as a function of time :

 A first order reaction is 87.5% complete in an hour. The rate constant of the reaction is

Half-life period of a second order reaction is

A first order reaction is 50% completed in 20 minutes at 27°C and in 5 min at 47°C. The energy of activation of the reaction is

For the first order reaction A → B + C, carried out at 27°C if 3.8 × 10^-16% of the reactant molecules exists in the activated state, the E_a (activation energy) of the reaction is

The rate constant, the activation energy and the Arrhenius parameter (A) of a chemical reaction at 25°C are 3.0 × 10^-4 s^-1, 104.4 kJ mol^-1 and 6.0 × 10^-4s^-1respectively. The value of the rate constant at T → ∞ is

The following mechanism has been proposed for the exothermic catalyzed complex reaction.

If k₁ is much smaller than k₂. The most suitable qualitative plot of potential energy (P.E.) versus  reaction coordinate for the above reaction.

The activation energy of a reaction at a given temperature is found to be 2.303 RT J mol^–1. The ratio of rate constant to the Arrhenius factor is

In a reaction, the thershold energy is equal to :

Consider  + heat, If activation energy for forward reaction is 100 kJ/mole then activation energy for backward reaction and heat of reaction is :

The first order rate constant k is related to temperature as log k = 15.0 - (10⁶/T). Which of the following pair of value is correct ?

When a graph between log K and 1/T is drawn a straight line is obtained. The temperature at which line cuts y-axis and x-axis.

The rate constant, the activation energy and the frequency factor of a chemical reaction at 25°C are 3.0 × 10^-2 s^-1, 104.4 KJ mol^-1 and 6.0 × 10¹⁴ s^-1 respectively. The value of the rate constant as T → ∞ is :

The rate data for the net reaction at 25°C for the reaction X + 2Y → 3Z are given below :

[X₀]   [Y₀]   Time required for [Z] to increase by 0.005 mol per litre.

0.01   0.01   72 sec

0.02   0.005  36 sec

0.02   0.01    18 sec

The intial rate (as given by Z) is :

The rate of production of NH₃ in N₂ + 3H₂ → 2NH₃ is 3.4 kg min^-1. The rate of consumption of H₂ is :

For a given reaction of first order it takes 20 min. for the conc. to drop from 1.0 M to 0.60 M. The time required for the conc. to drop from 0.60 M to 0.36 M will be :

For a first order reaction, the concentration of reactant :

Radioactivity of a sample (z = 22) decreases 90% after 10 years. What will be the half-life of the sample?

Mathematical representation for t_1/4 life for first order reaction is over is given by :

For a reaction A → Products, the conc. of reactant C₀, aC₀, a²C₀, a³C₀............ after time interval 0, t, 2t ............ where 'a' is constant. Then :

 Half-life is independent of conc. of A. After 10 minutes volume N₂ gas is 10 L and after complete reaction 50 L. Hence rate constant in min^-1 :

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 

In acidic medium the rate of reaction between (BrO₃)^- & Br^- ions is given by the expression, –[d(BrO₃^-) /dt] = K[BrO₃^-][Br^-][H ⁺]² It means :