Chemical Reactions and Entropy

What is the main reason endothermic reactions occur according to the text?

• Because the products are more stable than the reactants

• Because the entropy of the system decreases

• Because the enthalpy change alone cannot explain the occurrence of endothermic reactions

• Because the entropy of the system increases

What is entropy (S) a measure of in a given system?

• The number of possible arrangements of the particles and their energy

• The total energy of the particles in the system

• The stability of the chemical reactions

• The temperature change during a reaction

What happens to the entropy of a system as it becomes more disordered?

• The entropy decreases

• The entropy remains constant

• The entropy increases

• The entropy is not related to the order of the system

What happens to a system's stability when there is an increase in entropy?

• The system becomes energetically less stable

• The system becomes energetically more stable

• The system's temperature decreases

• The system's energy is completely lost

What is an example of a system becoming more disordered?

• A solid being compressed

• A liquid being frozen

• A solid being melted

• A gas being condensed

What state change of water is used to illustrate an increase in entropy?

• H2O(g) → H2O(s)

• H2O(l) → H2O(g)

• H2O(s) → H2O(l)

• H2O(l) → H2O(s)

Why are water molecules in the liquid state considered more disordered than in the solid state?

• They are in fixed positions and cannot move

• They are close together but arranged more randomly and can move around each other

• They have lower entropy in the liquid state

• They do not interact with each other in the liquid state

What is the entropy change when a solid melts into a liquid?

• The entropy decreases

• The entropy remains the same

• The entropy increases

• The entropy fluctuates unpredictably

Which system is energetically favorable?

• A system with lower entropy

• A system with higher entropy

• A system with no entropy change

• A system with maximum order

What happens to the entropy of the system during the thermal decomposition of calcium carbonate (CaCO3)?

• The entropy decreases

• The entropy remains constant

• The entropy increases

• The entropy first decreases then increases