Agniveer Army Technical Thermodynamics

The first law of thermodynamics states that ΔU = q + w. What does 'w' represent?

The standard enthalpy of formation (ΔH°f) of an element in its standard state is:

At constant pressure and temperature, a spontaneous process must have:

Which of the following is an extensive property in thermodynamics?

If the enthalpy change (ΔH) for a reaction is negative, the reaction is classified as:

Which of the following has the largest standard entropy (S°) at 298 K?

Which thermodynamic quantity is a state function?

For an endothermic reaction, which condition must be satisfied for the reaction to be spontaneous at high temperatures?

A gas expands from 1 L to 5 L against a constant external pressure of 2 atm. Calculate the work done by the gas (in L·atm). (Use w = −PΔV)

Which of the following statements correctly defines the First Law of Thermodynamics?

If a reaction releases 50 kJ of heat at constant pressure and the system does 10 kJ of work on the surroundings, what is the change in internal energy (ΔU)?

What is the standard molar enthalpy of formation (ΔH°f) of an element in its standard state?

A spontaneous reaction at 300 K has ΔH = −20 kJ/mol and ΔS = −50 J/(mol·K). Using ΔG = ΔH − TΔS, what can be concluded about this reaction?

For an endothermic process occurring at constant temperature and pressure, which condition must be satisfied for the process to be spontaneous?

The standard enthalpy of formation of H₂O(l) is -286 kJ/mol. If 9 g of water is formed from hydrogen and oxygen at constant pressure, what is the heat released?

A reaction has ΔH = -85 kJ/mol and ΔS = -0.15 kJ/(mol·K). At what temperature will this reaction become non-spontaneous?