NEET Chemical Kinetics — Set 8

Question 1

A zero-order reaction has a rate constant of $ 4.0 \times 10^{-3} \, \text{mol L}^{-1} \text{min}^{-1} $. If the initial concentration is $ 0.16 \, \text{mol L}^{-1} $, how long will it take for 50% decomposition?

Accepted Answer

For zero-order, $ t_{1/2} = \frac{[\text{R}]_0}{2k} $. Given: $ [\text{R}]_0 = 0.16 \, \text{mol L}^{-1} $, $ k = 4.0 \times 10^{-3} \, \text{mol L}^{-1} \text{min}^{-1} $. $ t_{1/2} = \frac{0.16}{2 \times 4.0 \times 10^{-3}} = \frac{0.16}{8.0 \times 10^{-3}} = 20 \, \text{min} $.

Question 2

A reaction follows zero-order kinetics with a rate constant of $ 4.0 \times 10^{-4} \, \text{mol L}^{-1} \text{s}^{-1} $. If the initial concentration is $ 0.08 \, \text{mol L}^{-1} $, what is the time required for complete decomposition?

Accepted Answer

For a zero-order reaction, $ t = \frac{[\text{R}]_0}{k} $ when $ [\text{R}] = 0 $. Given: $ k = 4.0 \times 10^{-4} \, \text{mol L}^{-1} \text{s}^{-1} $, $ [\text{R}]_0 = 0.08 \, \text{mol L}^{-1} $. $ t = \frac{0.08}{4.0 \times 10^{-4}} = 200 \, \text{s} $.

Question 3

A reaction has the rate law $ \text{Rate} = k[\text{A}]^{1/2}[\text{B}]^{3/2} $. What is the overall order?

Accepted Answer

Overall order = $ \frac{1}{2} + \frac{3}{2} = \frac{1}{2} + \frac{3}{2} = 2 $.

NEET Chemistry: Chemical Kinetics — Practice Set 8

Q1. A zero-order reaction has a rate constant of \( 4.0 \times 10^{-3} \, \text{mol L}^{-1} \text{min}^{-1} \). If the initial concentration is \( 0.16 \, \text{mol L}^{-1} \), how long will it take for 50% decomposition?

Q2. A reaction follows zero-order kinetics with a rate constant of \( 4.0 \times 10^{-4} \, \text{mol L}^{-1} \text{s}^{-1} \). If the initial concentration is \( 0.08 \, \text{mol L}^{-1} \), what is the time required for complete decomposition?

Q3. A reaction has the rate law \( \text{Rate} = k[\text{A}]^{1/2}[\text{B}]^{3/2} \). What is the overall order?

Q4. For the reaction \( 2\text{A} \to \text{B} \), the rate of disappearance of A is \( 0.04 \, \text{mol L}^{-1} \text{min}^{-1} \). What is the rate of formation of B?

Q5. For the reaction \( \text{A} + \text{B} \to 2\text{C} \), the rate of disappearance of B is \( 0.06 \, \text{mol L}^{-1} \text{s}^{-1} \). What is the rate of formation of C?

Q6. For the reaction \( \text{A} + 3\text{B} \to 2\text{C} \), the rate of disappearance of B is \( 0.09 \, \text{mol L}^{-1} \text{s}^{-1} \). What is the rate of formation of C?

Q7. For the reaction \( 2\text{A} + 3\text{B} \to 4\text{C} \), the rate of formation of C is \( 0.08 \, \text{mol L}^{-1} \text{min}^{-1} \). What is the rate of disappearance of A?

Q8. The molecularity of the elementary step \( \text{Cl}_2 + \text{CHCl}_3 \to \text{HCl} + \text{CCl}_4 \) is:

Q9. For the reaction \( 2\text{A} + \text{B} \to 4\text{C} \), the rate of formation of C is \( 0.16 \, \text{mol L}^{-1} \text{min}^{-1} \). What is the rate of disappearance of A?

Q10. A first-order reaction has a rate constant of \( 0.0139 \, \text{min}^{-1} \). What is the time for 60% completion?