Thermodynamics

For a reversible process, the change in entropy of the universe is:

A sample of an ideal gas undergoes a cyclic process. The net work done on the gas in the cycle is positive. What can be concluded about the heat exchange ($q$) during this cycle?

Which of the following processes is associated with a decrease in entropy?

In an adiabatic free expansion of an ideal gas, which of the following is true?

A gas expands from 10 L to 20 L against a constant external pressure of 2 atm. If the internal energy of the system decreases by 500 J, what is the heat change (q) of the process? (1 L·atm = 101.3 J).

For a reversible process, the change in entropy of the universe is:

An ideal gas undergoes a cyclic process. The net work done on the gas is positive. What can be concluded about the heat exchange (q) during this cycle?

A reaction has a standard enthalpy change of +100 kJ/mol and a standard entropy change of +250 J/mol·K. At what temperature will the reaction become spontaneous?

For which of the following processes is the change in internal energy equal to the heat absorbed by the system?

The enthalpy of combustion of carbon is -393.5 kJ/mol. What is the heat released when 120 grams of carbon are completely combusted? (Molar mass of carbon = 12 g/mol)

Which of the following processes is associated with a decrease in entropy?

The specific heat capacity of a substance is given by cp = A + BT. The amount of heat required to change the temperature of 1 mol of the substance from T1 to T2 at constant pressure is

In an adiabatic free expansion of an ideal gas, which of the following is true?

Which of the following conditions ensures a spontaneous reaction at all temperatures?

The enthalpy of neutralization of a strong acid and a strong base is approximately constant at -57.3 kJ/mol. What is the reason for this consistency?

For a non-spontaneous process, what is the change in Gibbs free energy (ΔG)?

A system absorbs 150 J of heat from the surroundings and does 50 J of work on the surroundings. What is the change in the internal energy of the system?

What is the condition for a process to be spontaneous at high temperatures?

The change in enthalpy of a reaction is -40 kJ and the change in entropy is -100 J/K. At what temperature (in K) is the reaction at equilibrium?

What is the value of the molar heat capacity at constant volume (Cv​) for a diatomic ideal gas?

An ideal gas expands adiabatically into a vacuum. Which of the following is true?

Which of the following is a state function?

For a certain process, the volume of a gas decreases while the temperature remains constant. What can be said about the work done on the gas?

The bond enthalpy of H-H is 436 kJ/mol and that of Cl-Cl is 242 kJ/mol. The bond enthalpy of H-Cl is 431 kJ/mol. What is the enthalpy of the reaction H2(g) + Cl2(g) -> 2HCl(g)?

In an isobaric process, which of the following remains constant?

A process has a positive enthalpy change ($DeltaH>0$) and a positive entropy change ($DeltaS>0$). Under what condition will this process be spontaneous?

In an adiabatic expansion of a gas against an external pressure, which of the following is true?

The maximum amount of useful work a system can perform at a constant temperature and pressure is equal to the decrease in its:

A chemical reaction has a negative change in enthalpy ($\Delta H<0$) and a negative change in entropy ($\Delta S<0$). Under what conditions will the reaction be spontaneous?

The efficiency of a Carnot engine is 50%. If the temperature of the cold reservoir is 300 K, what is the temperature of the hot reservoi