IIT/JEE Chemistry Practice #29: Thermodynamics

The video tutorial covers three key questions related to thermodynamics. The first question discusses the entropy changes during the vaporization of water, emphasizing the relationship between system and surroundings. The second question examines a heat engine's compliance with the first law of thermodynamics, highlighting energy conservation principles. The third question explores activation energies in endothermic reactions, comparing forward and backward reactions. The tutorial suggests reviewing classical physics and chemistry series for a deeper understanding of these concepts.

What happens to the entropy of the surroundings when water is vaporized at its boiling point?

• It becomes zero.

• It increases.

• It decreases.

• It remains constant.

Which statement about the work done by a heat engine is true according to the first law of thermodynamics?

• The work done is unrelated to the heat absorbed.

• The work done is greater than the total heat absorbed.

• The work done is equal to the total heat absorbed.

• The work done is less than the total heat absorbed.

What is the primary focus of the first law of thermodynamics?

• Chemical equilibrium.

• Entropy changes.

• Energy conservation.

• Phase transitions.

In an endothermic reaction, how does the activation energy for the backward reaction compare to the forward reaction?

• There is no relation.

• Backward is less than forward.

• Backward is greater than forward.

• They are equal.

What is a key characteristic of an endothermic reaction?

• No energy change occurs.

• Products have higher energy than reactants.

• Products have lower energy than reactants.

• Energy is released to the surroundings.

Which law of thermodynamics is primarily concerned with the direction of energy transfer?

• Zeroth law

• Third law

• First law

• Second law

What should you review to better understand the relationship between entropy and phase changes?

• Classical physics series

• Organic chemistry series

• Quantum mechanics series

• Biology series