concentration of A is 5 M then concentration of B after 20 min is

2. 3.60 M

If  rate of reaction doubles when the temperature is raised from 20°C to 35°C , then the activation energy for the reaction will be :  (R=8.314 J mol^-1 K^-1)

A reaction having equal energies of activation for forward and reverse reactions has

For the reaction,

$N_2{O}_5\left(g\right)\to 2N{O}_2\left(g\right)+\frac{1}{2}{O}_2\left(g\right)$

the value of rate of disappearance of ${\mathrm{N}}_2{\mathrm{O}}_5$ is given as $6.25\times {10}^{-3} mol L^{-1}{s}^{-1}$. The rate of formation of $N{O}_2 and O_2$ is given respectively as :

For an endothermic reaction, energy of activation is E_a and enthalpy of reaction is $∆$H (both of these in kJ/mol). Minimum value of E_a will be

Half-life period of a first order reaction is 1386s. The specific rate constant of the reaction

is

For the reaction A+B $\to$products, it is observed that

(1) On doubling the initial concentration of A only, the rate of reaction is also doubled and

(2) On doubling the initial concentrations of both A and B, there is a change by a factor of

8 in that rate of the reaction

The rate of this reaction is, given by

In the reaction, BrO^-₃(aq) + 5Br^-(aq) + 6H⁺ $\to$3Br₂(l) + 2H₂O(l)

The rate of appearance of bromine (Br₂) is related to rate of disappearance of bromide

ions as following 

The rate constants k₁ and k₂ for two different reactions are 10¹⁶ e^-2000/T and 10¹⁵ e^-1000/T  , respectively. The temperature at which k₁=k₂ is:

The bromination of acetone that occurs in acid solution is represented by this equation.

${\mathrm{CH}}_3{\mathrm{COCH}}_3\left(\mathrm{aq}\right) + {\mathrm{Br}}_2\left(\mathrm{aq}\right) \stackrel{ }{\to }{\mathrm{CH}}_3{\mathrm{COCH}}_2\mathrm{Br}\left(\mathrm{aq}\right) + {\mathrm{Br}}^{-}\left(\mathrm{aq}\right)$

These kinetic data were obtained for given reaction concentrations. 

                   Initial concentrations, M

  $\left[{\mathrm{CH}}_3{\mathrm{COCH}}_3\right]$                $\left[{\mathrm{Br}}_2\right]$         $\left[{\mathrm{H}}^{+}\right]$

       0.30                        0.05           0.05

       0.30                        0.10           0.05

       0.30                        0.10           0.10

       0.40                        0.05           0.20

Initial rate, disappearance of Br₂, Ms^-1

                        5.7X10^-5

                        5.7X10^-5

                        1.2X10^-4

                        3.1X10^-4

Based on these data, the rate equation is

In a first order reaction A $\stackrel{ }{\to }$ B, if k is rate constant and initial concentration of the reactant A is 0.5 M then the half-life is :

If 60% of a first order reaction was completed in 60 min, 50% of the same reaction would be completed in approximately.

(log 4=0.60, log 5=0.69)

For the reaction 2A + B $\stackrel{ }{\to }$ 3C + D which of the following does not express the reaction rate ?

The units of rate constant and rate of reaction are same for: 

Rate constant K= $1.2\times {10}^3$ mol L^-1 s^-1 and $E_a =2.0\times {10}^{2}KJ mo{l}^{-1}. When T\to \infty$, A is equal to 

The effect of a catalyst in a chemical reaction is to change the 

When the concentration of reactant was made 4 times rate of reaction becomes 8 times. The order of reaction with respect to that reactant is 

The rate constant for a reaction of zero-order in A is 0.0030 mol L^-1 s^-1. How long will it take for the initial concentration of A to fall from 0.10 M to 0.075 M?

A first order reaction is 15% completed in 20 minutes. Time required  to complete 60% of the reaction is:

Assertion : If the activation energy of reaction is zero temperature will have no effect on the rate constant.

Reason : Lower the activation energy fasten is the reaction.

Assertion : For a reaction $\mathrm{A}\left(\mathrm{g}\right)\to \mathrm{B}\left(\mathrm{g}\right)$

                                 $—{\mathrm{r}}_{\mathbf{e}}=2.5 {\mathrm{P}}_{\mathrm{A}} \mathrm{at} 400\mathrm{K}$

                                 $—{\mathrm{r}}_{\mathbf{e}}=2.5 {\mathrm{P}}_{\mathrm{A}} \mathrm{at} 600\mathrm{K}$

                  activation energy is 4135 J/mol.

Reason : Since for any reaction, values of rate constant at two different temp is same therefore

               activation energy of the reaction is zero.

If concentration are measured in mole/litre and time in minutes , the unit for the rate constant of a $3^{rd}$ order reaction are

Following reaction was carried out at 300 K.

$2S{O}_2\left(g\right)+O_2\left(g\right)\to 2S{O}_3\left(g\right)$

The rate of formation of $S{O}_3$ is related to the rate of disappearance of $O_2$  by following expression: 

Which of the following rate laws has an over all order of 0.5 for the reaction A+B+C$\to$product-

For the system $A_2\left(g\right)+B_2\left(g\right) 2AB\left(g\right),∆H=-80kJ$ If the activation energy for the forward step is 100 kcal/mol.What is the ratio of temperature at which the forward and backward reaction shows the same % change of rate constant per degree rise of temperature ? (1 cal= 4.2 J)

A first order reaction takes 40 min for 30% decomposition. t_1/2 for this reaction is: 

3. 55.3 min.                                                 

For a reaction of the type 2A+B $\to$2C, the rate of the reaction is given by $k{\left[A\right]}^2\left[B\right]$. When the volume of the reaction vessel is reduced to 1/4 th of the original volume, the rate of reaction changes by a factor of

From the following data , the order with respect to A, B, C respectively is : 

[A]         [B]        [C]                   rate (M/sec.)

0.2        0.1       0.02                 $8.08\times {10}^{-3}$

0.1        0.2       0.02                 $2.01\times {10}^{-3}$

0.1        1.8       0.18                 $6.03\times {10}^{-3}$

0.2        0.1       0.08                 $6.464\times {10}^{-2}$

The elementary reaction A+B$\to$products has $k=2\times {10}^{-5} M^{-1} S^{-1}$ at a temperature of $27°$C. Several experimental runs are carried out using stoichiometric proporation. The reaction has a temperature coefficent value of 2.0. At what temperature should the reaction be carried out if inspite of halving the concentrations, the rate of reaction is desired to be 50% higher than a previous run.

(Given $\frac{\mathcal{l}n6}{\mathcal{l}n2}=2.585)$

When the temperature of a reaction increases from ${27}^{0}C$ to ${37}^{0}C$, the rate increases by 2.5 times, the activation energy in the temperature range is :

1. 53.6 KJ