Class 12 Chemistry Important Chapter 4 Chemical kinetics

Class 12 Chemistry Important Chapter 4 Chemical kinetics Solutions English Medium As Per The New Syllabus to each chapter is provided in the list so that you can easily browse through different chapters ASSEB Class 12 Chemistry Important Solutions in English and select need one. AHSEC Class 12 Chemistry Additional Notes Download PDF. HS 2nd Year Chemistry Additional Solutions.

Class 12 Chemistry Important Chapter 4 Chemical kinetics

Also, you can read the NCERT book online in these sections Solutions by Expert Teachers as per Central Board of Secondary Education (CBSE) Book guidelines. ASSEB Class 12 Chemistry Additional Question Answer are part of All Subject Solutions. Here we have given HS 2nd Year Chemistry Important Solutions English Medium for All Chapters, You can practice these here.

Chemical kinetics

Chapter: 4

PART – I

IMPORTANT QUESTION AND ANSWER

1. What is the rate of a chemical reaction?

Ans: The rate of a chemical reaction is the change in concentration of a reactant or product per unit time.

2. Define instantaneous rate of reaction.

Ans: Instantaneous rate is the rate of reaction at a particular instant of time, obtained by measuring the slope of the tangent to the concentration vs time curve at that point.

3. What factors affect the rate of a chemical reaction?

Ans: Concentration of reactants, temperature, catalyst presence, and pressure (for gases) affect the rate of a reaction.

4. What is the order of a reaction?

Ans: The order of a reaction is the sum of the powers of the concentration terms in the rate law expression.

5. How is the rate constant (k) related to temperature?

Ans: Rate constant increases with temperature; 

quantitatively expressed by the Arrhenius equation:

k = Ae^−Ea/RT

6. What is molecularity?

Ans: Molecularity is the number of reactant molecules that collide simultaneously in an elementary reaction to produce a reaction event; it can be unimolecular, bimolecular, or termolecular.

7. What is a pseudo first order reaction?

Ans: A reaction that is higher order but behaves like a first order reaction because the concentration of one reactant is in large excess and remains nearly constant.

8. What is activation energy?

Ans: Activation energy is the minimum energy that reacting molecules must have for a reaction to occur.

9. How does concentration affect the rate of a second order reaction?

Ans: For a second order reaction, if the concentration of the reactant is doubled, the rate increases by four times; if halved, the rate decreases to one-fourth.

10. What is the half-life of a first order reaction?

Ans: The half-life is the time required for the concentration of a reactant to reduce to half its initial value and is given by t:

​independent of initial concentration.

11. Define order of reaction.

Ans. The sum of the powers of the concentration of the reactants of a chemical reaction in the rate law expression is called the order of that chemical reaction.

12. State the role of activated complex in a reaction and state its relation with activation energy.

Ans : Activated complex is the intermediate compound formed by reactants, which is highly unstable and readily changes into product.Those reactants which possess activation energy and collide in proper orientation can form activated complex which can easily form products.

Lower the activation energy, more easily activated complex will be formed and faster will be the reaction. Activation energy = energy of activated complex -energy of reactants. 

13. Define each of the following:

(i) Specific rate of reaction.

Ans: Specific rate of reaction: It is equal to the rate of reaction when molar concentration of reactants is unity. Its unit depends upon the order of reaction.