Which of the following is true about entropy in a closed system?
a) Entropy decreases over time
b) Entropy remains constant
c) Entropy increases over time
d) Entropy is independent of time
What is the second law of thermodynamics?
a) Entropy always decreases in isolated systems
b) Entropy is constant for all reactions
c) The total entropy of an isolated system tends to increase
d) The total entropy of a system can never increase
What does spontaneity of a process depend on?
a) The initial and final states of the system
b) The total energy of the system
c) The change in entropy and enthalpy
d) The type of reaction involved
Which of the following reactions is spontaneous at all temperatures?
a) Freezing of water
b) Boiling of water
c) Sublimation of ice
d) Combustion of carbon
Which of the following increases the entropy of a system?
a) Freezing
b) Condensation
c) Evaporation
d) Deposition
In a spontaneous process, the Gibbs free energy change is:
a) Positive
b) Negative
c) Zero
d) Variable
What is the relationship between entropy (S) and temperature (T) in an isothermal reversible process?
a) S = T
b) ΔS = Q/T
c) S = Q × T
d) ΔS = T × Q
Which of the following conditions is necessary for a process to be spontaneous?
a) Positive change in enthalpy
b) Negative change in entropy
c) Negative change in enthalpy and positive change in entropy
d) Positive change in enthalpy and entropy
At absolute zero temperature, the entropy of a perfect crystal is:
a) Zero
b) Maximum
c) Negative
d) Indeterminate
When the temperature of a system increases, the entropy of the system generally:
a) Decreases
b) Increases
c) Remains constant
d) Becomes zero
What does the symbol ΔS represent in thermodynamics?
a) Change in pressure
b) Change in volume
c) Change in entropy
d) Change in temperature
For a reaction to be spontaneous at high temperatures, what should be the sign of ΔH and ΔS?
a) ΔH positive, ΔS negative
b) ΔH negative, ΔS negative
c) ΔH positive, ΔS positive
d) ΔH negative, ΔS positive
The entropy of a gas compared to a liquid is:
a) Higher
b) Lower
c) Equal
d) Indeterminate
Which of the following processes is associated with a decrease in entropy?
a) Sublimation
b) Evaporation
c) Freezing
d) Melting
If the change in entropy is negative for a process, the process is:
a) Spontaneous at all temperatures
b) Non-spontaneous at all temperatures
c) Spontaneous only at low temperatures
d) Spontaneous only at high temperatures
In a reversible reaction, what happens to the entropy of the system at equilibrium?
a) It increases
b) It decreases
c) It remains constant
d) It becomes zero
The process in which a solid turns into a gas is called:
a) Deposition
b) Sublimation
c) Condensation
d) Freezing
Which of the following is a factor that affects the spontaneity of a reaction?
a) Activation energy
b) Reaction mechanism
c) Change in entropy and enthalpy
d) Concentration of reactants
In an endothermic reaction, the change in enthalpy (ΔH) is:
a) Negative
b) Positive
c) Zero
d) Indeterminate
A process that leads to an increase in disorder in the system is said to:
a) Be exothermic
b) Be reversible
c) Increase entropy
d) Decrease entropy
Which of the following changes will lead to a decrease in entropy?
a) Solid to liquid
b) Gas to liquid
c) Liquid to gas
d) Solid to gas
Which of the following is true about a spontaneous process?
a) The total entropy of the universe decreases
b) The total entropy of the universe remains constant
c) The total entropy of the universe increases
d) The total entropy of the system remains constant
The entropy change of the surroundings depends on:
a) The temperature of the surroundings
b) The pressure of the surroundings
c) The volume of the surroundings
d) The concentration of the surroundings
What happens to the entropy of a system during an irreversible process?
a) It remains constant
b) It decreases
c) It increases
d) It fluctuates
Which of the following processes is an example of an irreversible process?
a) Boiling of water at 100°C
b) Melting of ice at 0°C
c) Expansion of gas in a cylinder
d) Compression of gas in a piston
Which of the following is an example of a spontaneous process?
a) Freezing of water at 0°C
b) Melting of ice at 0°C
c) Combustion of fuel
d) Condensation of steam at 100°C
In an isothermal expansion of an ideal gas, the change in entropy is:
a) Zero
b) Negative
c) Positive
d) Undefined
