Q1: Define Chemical Energetics.

Q2: What is the significance of energy in determining the feasibility and direction of chemical reactions?

Q3: What is the distinction between the "system" and "surroundings" in the context of energy transfer and chemical reactions, and provide an example to illustrate this concept?

Q4: What are thermochemical reactions, and how do exothermic and endothermic reactions differ in terms of energy transfer, providing examples and equations to illustrate each type?

Classify the following processes as exothermic and endothermic.

  1. Freezing of water
  2. Combustion of methane
  3. Sublimation of dry ice
  4. H2O (g) → H2O (l)
  5. Decomposition of limestone

Q5: Define a chemical system. How it interacts with its surroundings during a reaction.

Ans: A chemical system is a region where chemical reactions occur, involving reactants.

Q6: How can you differentiate between exothermic and endothermic reactions based on the temperature change of the surroundings?

Q7: Why combustion reactions are typically classified as exothermic reactions.

Q8: Provide an example of an endothermic reaction occurring in everyday life other than given in the book.

Q9: Discuss bond energy and bond dissociation energy.

Calculate the enthalpy of the following reaction from the given bond energy data. Bond energy of H-H, F-F, H-F bonds are 436 kJ/mol, 155 kJ/mol and 567 kJ/mol respectively.

Find the energy change in the following reaction using the bond energies given.

Bond energies: C-H 412 kJ, O=O 496 kJ, C=O 743 kJ, H-H 436 kJ.

H-C-H + 2O=O → O=C=O + 2H-H

Explain why the reaction is exothermic or endothermic using bond energies.

Q10: Discuss in detail the concept of activation energy.

Q11: Explain the effect of catalyst on energy of activation. Also show it graphically.

1. What is a catalyst?

2. How do catalysts work?

3. Is each of the following reactions endothermic or exothermic?

  1. The temperature started at 21°C and finished at 46°C.
  2. The temperature started at 18°C and finished at 14°C.
  3. The temperature started at 19°C and finished at 25°C.

Q12: Explain how respiration (aerobic and anaerobic), an exothermic process, provides energy for biological systems and lipids as reserve stores of energy.

1. How does anaerobic respiration differ from aerobic respiration in terms of energy production?

2. What role do energy-rich molecules like ATP play in biological systems?

3. Why respiration is considered an exothermic process and how this benefits biological systems?

4. Discuss the significance of lipids as energy reserves in organisms, especially during times of increased demand.