The half-life time for the decomposition of a substance dissolved in ${\mathrm{CCl}}_4$ is 2.5 hours at $\mathrm{30 }°$C. The amount of substance that will be left after 10 hours if the initial weight of the substance is 160 gm is:

1.	20 gm	2.	30 gm
3.	40 gm	4.	10 gm

Given the following reaction:
N₂O₅   as   N₂O₅   ⇌ 2NO₂ + (1/2)O₂
The values of rate constants for the above reaction are 3.45 × 10^-5 and 6.9 × 10^-3 at 27 ^oC and 67 ^oC respectively. The activation energy for the above reaction is : 

1. $102$ $\times {10}^2$ $J$ $$ $$                                    

2. $488.5$ $kJ$

3. $112$ $J$ $$                                             

4. $112.5$ $kJ$

What is the percentage of the reactant molecules crossing over the energy barrier at 325 K?

Given that $∆{\mathrm{H}}_{325}=0.12$ $\mathrm{kcal},$ ${\mathrm{E}}_{\mathrm{a}\left(\mathrm{b}\right)}=+0.02$ $\mathrm{kcal}$

1 mole of a gas changes linearly from its initial state (2 atm, 10 lt) to its final state (8 atm, 4 lt). The maximum rate constant is equal to 20 $se{c}^{-1}$ and the value of activation energy is 40 kJ, assuming that the activation energy does not change in this temperature range. The value of the rate constant, at the maximum temperature that the gas can attain, is: 

1. $0.56$ $\times$ ${10}^{-3}$ $se{c}^{-1}$                                          

2. $3.16$ $\times$ ${10}^{-3}$ $se{c}^{-1}$

3. $1.56$ $\times$ ${10}^{-3}se{c}^{-1}$                                          

4. $5.12$ $\times$ ${10}^{-3}$ $se{c}^{-1}$

A first-order reaction was started with a decimolar solution of the reactant. After 8 minutes and 20 seconds, its concentration was found to be M/100. The rate constant of the reaction will be:

1. $4.6$ $\times$ ${10}^{-3}se{c}^{-1}$                                      

2. $16.6$ $\times$ ${10}^{-3}$ $se{c}^{-1}$

3. $24.6$ $\times$ ${10}^{-3}$ $se{c}^{-1}$                                   

4. $40.6$ $\times$ ${10}^{-3}$ $se{c}^{-1}$

The decomposition of A into product has value of k as \(4.5 \times 10^3 \mathrm{~s}^{-1} \text { at } 10^{\circ} \mathrm{C}.\) Energy of activation of the reaction is \(60 \mathrm{~kJ}~mol^{-1}.\) The temperature at which value k would become \(1.5\times10^4~s^{-1}\) is : 

For the reaction 2N₂O₅(g) → 4NO₂(g) + O₂(g)$,$the concentration of $$ $N{O}_2$ increases by 2.4 × 10^-2 mol L^-1

in 6 seconds. The rate of appearance of $N{O}_2$ and the rate of disappearance of $N_2{O}_5$ , respectively, are:

1. 2 x 10^-3 mol L^-1 sec^-1, 4 x 10^-3 mol L^-1 sec^-1

2. 2 x 10^-3 mol L^-1 sec^-1, 1 x 10^-3 mol L^-1 sec^-1

3. 2 x 10^-3 mol L^-1 sec^-1, 2 x 10^-3 mol L^-1 sec^-1

4. 4 x 10^-3 mol L^-1 sec^-1, 2 x 10^-3 mol L^-1 sec^-1

The rate constant of a particular reaction has the dimension of frequency. The order of the reaction is: 

1. Zero.                                                     

2. First.

3. Second.                                                 

4. Fractional.

For the reaction, C₂H₅I + OH^- → C₂H₅OH + I^- the rate constant was found to have a value of 5.03 × 10^-2 moI^-1 dm³ s^-1 at 289 K and 6.71 mol^-1 dm³ s^-1 at 333 K. 

The rate constant at 305 K will be: 

$1.$ $1.35$ $mo{l}^{-1}$ $d{m}^3$ $s^{-1}$                  

$2.$ $0.35$ $mo{l}^{-1}$ $d{m}^3$ $s^{-1}$

$3.$ $3.15$ $mo{l}^{-1}$ $d{m}^3$ $s^{-1}$                    

$4.$ $7.14$ $mo{l}^{-1}$ $d{m}^3$ $s^{-1}$

The first order rate constant for a certain reaction increases from\(1.667 \times 10^{-6} \mathrm{~s}^{-1} \text { at } 727^{\circ} \mathrm{C} \text { to } 1.667 \times 10^{-4} \mathrm{~s}^{-1} \text { at } 1571{ }^{\circ} \mathrm{C}.\) The rate constant at \(1150^{\circ} \mathrm{C}\) is: 
(assume activation energy is constant over the given temperature range)