For the reaction, \(\mathrm{N}_2+3 \mathrm{H}_2 \rightarrow 2 \mathrm{NH}_3,\) if, \(\dfrac{d[NH_{3}]}{dt} \ = \ 2\times 10^{-4} \ mol \ L^{-1} \ s^{-1}\), the value of  \(\dfrac{-d[H_{2}]}{dt}\) would be:
1. \(3 \times 10^{-4} \mathrm{~mol} \mathrm{~L}^{-1} \mathrm{~s}^{-1} \)
2. \(4 \times 10^{-4} \mathrm{~mol} \mathrm{~L}^{-1} \mathrm{~s}^{-1} \)
3. \(6 \times 10^{-4} \mathrm{~mol} \mathrm{~L}^{-1} \mathrm{~s}^{-1} \)
4. \(1 \times 10^{-4} \mathrm{~mol} \mathrm{~L}^{-1} \mathrm{~s}^{-1}\)

For the reaction, \(2 A+B \rightarrow 3 C+D\)

Which of the following is an incorrect expression for the rate of reaction?

Which of the following statements about the order of reaction is incorrect?

When the initial concentration of a reactant is doubled in a reaction, its half-life period is not affected. The order of the reaction will be:
1. 0
2. 1
3. 1.5
4. 2 

The mechanism of a hypothetical reaction

X₂ + Y₂ → 2XY  is given below: 
(i) X₂ → X + X (Fast)
(ii) X + Y₂  ⇄  XY + Y (slow)
(iii) X + Y → XY (Fast)

The overall order of the reaction will be:

1. 2

2. 0

3. 1.5

4. 1

If $∆\mathrm{H}$ of a reaction is 100 kJ mol^-1, then the activation energy for the forward reaction must be

1. Greater than 100 kJ mol^-1

2. Less than 100 kJ mol^-1

3. Equal to 100 kJ mol^-1

4. None of the above.

At 400 K, the energy of activation of a reaction is decreased by 0.8 kcal in the presence of a catalyst. As a result, the rate will be:

The following data were obtained during the first-order thermal decomposition of $S{O}_{2}C{l}_2$ at a constant volume.

SO₂Cl₂(g) → SO₂(g) + Cl₂(g)

The rate of the reaction when total pressure is 0.65 atm will be:

1. $7.8$ $\times$ ${10}^{-4}$ $s^{-1}$ $atm.$                                  

2. $0.8$ $\times$ ${10}^{-4}$ $s^{-1}$ $atm.$

3. $2.4$ $\times$ ${10}^{-2}$ $s^{-1}$ $atm.$                                   

4. $6.1$ $\times$ ${10}^{-8}$ $s^{-1}$ $atm.$

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

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