Important Questions from Class 12 Chemistry Chapter 3, Download PDF

Important questions from Class 12 Chemistry Chapter 3, Chemical Kinetics, are asked in the board exams. Students should focus on numericals related to the rate of reaction, rate law, and rate constant, order and molecularity of reactions, and units of rate constant for different reaction orders.

Integrated rate equations for zero and first-order reactions, calculation of half-life, and graph-based questions are very important for board exam preparation. 

Questions based on the Arrhenius equation, activation energy, and temperature dependence of the rate constant are also commonly asked. Additionally, conceptual questions on factors affecting the rate of reaction and collision theory play a key role in scoring well in the board exams.

Chemical Kinetics Class 12 Chemistry Important Question

Below are the Class 12 Chemistry Chemical Kinetics MCQs and Important Questions Chapter 3, specially selected for board exam and competitive exam preparation.

These questions cover important topics such as rate of reaction, order and molecularity, integrated rate equations, half-life, Arrhenius equation, activation energy, and factors affecting the rate of reaction. 

Practicing these Important Questions from Class 12 Chemistry Chapter 3 will help strengthen conceptual understanding and improve accuracy in the Class 12 board exams.

1. Which of the following oxidation state is common for lanthanides?

(1) +2 (2) +3

(3) +4 (4) +

2. Account for the following trends in atomic and ionic radii of transition elements.

a) Ions of the same charge in a given series (3d, 4d or 5d) show progressive decrease in radii with increasing atomic number.

b) The atomic radii of elements in 4d series are more than that of corresponding elements in 3d series.

c) The atomic radii of the corresponding elements in 4d series and 5d series are virtually the same.

3. What is the structure of chromate ion ((CrO42–)?

4. What is the magnetic moment of an atom having d10 configuration?

5. Among the following transition elements which one has a completely filled d orbital?

(1) Ag (2) Ti

(3) Mo (4) Ni

6. Write the preparation of K2Cr2O7 from Chromite ore. 

7. What is lanthanoid contraction? What are the consequences of lanthanoid contraction?                       

8. a) Transition elements are ‘d’ block elements.

i) Write any four characteristic properties of transition elements. 

ii) Cr2+ and Mn3+ have d4 configuration. But Cr2+ is reducing and Mn3+ is oxidising. Why? 

What is the structure of chromate ion ((CrO42–)?  

9. Potassium dichromate is a very useful oxidizing agent.

(i) Name the ore of Potassium dichromate.

(ii) Explain the preparation of Potassium dichromate from Sodium chromate. 

10. The transition element present in ‘bronze’ is _____ 

Last Minute Preparation Tips for Class 12 Chemistry Chapter 3 (Chemical Kinetics)

Proper revision in the final hours can significantly improve your score on the board exam. Focus on clarity of concepts and quick formula recall rather than learning new topics.

• Revise all important formulas (rate law, integrated rate equations, Arrhenius equation).

• Learn units of rate constant (k) for zero, first, and second order reactions.

• Practice numericals on half-life (t½) for zero and first order reactions.

• Revise graphs:

• Concentration vs Time

• log[A] vs Time (first order straight line)

• Understand the difference between order and molecularity.

• Revise factors affecting rate of reaction (temperature, concentration, catalyst, surface area).

• Practice 4–5 important board exam PYQs for confidence.

• Avoid new topics at the last moment — focus only on revision.