The half life period of gaseous substance undergoing thermal decomposition was measured for various initial pressure ‘P’ with the following result. 

P(mm)       250     300      400     450

$t_{1/2}$(min)   136    112.5     85      75.5

Calculate the order of reaction.

(A) 2                                                 

(B) 4

(C) 6                                                 

(D) 10

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.

The reaction of iodomethane with sodium ethoxide proceeds as : $Et{O}^{⊝}+MeI\to EtOMe+ I^{⊝}$

A plot of log $\left\{\frac{\left[MeI\right]}{\left[Et{O}^{⊝}\right]}\right\}$on the Y-axis against 't' on the X-axis gives a straight line with a positive slope. What is the order of the reaction ?

(1) Second                                                

(2) First

(3) Third                                                   

(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: 

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

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

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

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

A plot of ln rate Vs ln C for the nth order reaction gives 

(1) a straight line with slope n and intercept ln $k_n$

(2) a straight line with slope (n – 1)

(3) a straight line with slope ln $k_n$ and intercept ‘n’

(4) a straight line with slope –n and intercept $k_n$

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)

The solvolysis of 2-chloro-2-methyl propane in aqueous acetone: $H_{2}O+{\left(C{H}_3\right)}_{3}C-Cl\to HO-C{\left(C{H}_3\right)}_3+H^{+}C{l}^{-}$ has a rate equation. 

Rate =$K\left[\right(C{H}_3 {)}_3 C – Cl].$From this it may be inferred that the energy profile of the reaction leading from reactants to products is

(A)                                 

(B) 

(C)                             

(D) 

The thermal decomposition of a compound is of first order. If 50 % of a sample of the compound decomposes in 120 minutes, how long will it take for 90 % of the compound to decompose?

1. 399 min                                                        

2. 410 min

3. 250 min                                                        

4. 120 min

The half-life for radioactive decay of ${}^{14}C$ is 5730 y. An archaeological artifact containing wood had only 80 % of the ${}^{14}C$ found in a living tree. The age of the sample will be:

1. 1657.3 y                                                

2. 1845.4 y

3. 1512.4 y                                                

4. 1413.1 y