Question Bank: Thermodynamics

What is the change in internal energy when no heat is added to the system, but work is done on it?

If a system does work on its surroundings and no heat is exchanged, what equation describes the change in internal energy?

When heat is removed from a system and no work is done, what can be said about the change in internal energy?

What type of wall would a system have if it cannot exchange heat but can do work?

In a closed system, if a gas expands against a constant external pressure, which of the following statements is TRUE?

If 100 J of work is done on a system and no heat is transferred, what is the change in internal energy?

In which situation is the internal energy of a system unchanged?

If the internal energy of a system decreases due to work done by the system, which of the following must be true?

In a gas system, if 500 J of heat is added and the system does 200 J of work, what is the change in internal energy?

The mathematical expression ∆U = q + w is associated with which fundamental principle?

What type of system exchanges both energy and matter with its surroundings?

If work is done on the system and heat is lost, how would the internal energy change?

What is the effect on internal energy if a perfectly insulated system expands against an external pressure?

A piston compresses an ideal gas. If the work done on the gas is positive, what happens to its internal energy?

When examining a reaction that produces a gas in a closed container, what concept helps predict the pressure change as the volume changes?

What is a thermodynamic system?

Which of the following describes an open system?

What is the primary purpose of calorimetry in scientific experiments?

In a closed system, what can be exchanged with the surroundings?

In which type of calorimeter is the change in internal energy (∆U) measured?

Which of the following is an example of an isolated system?

How is heat absorbed by a calorimeter calculated?

What does the state of a thermodynamic system depend on?

What does a negative value of ∆H indicate about a reaction?

What is the role of boundaries in a thermodynamic system?

What is the relationship between ∆U and ∆H at constant pressure?

Which statement is true about state functions?

Which factor does NOT affect the heat capacity of a calorimeter?

The heat content of a system at constant pressure is termed as:

At what conditions is the measurement of enthalpy (∆H) commonly performed?

Which of the following is NOT a state variable?

What happens to the heat of reaction (qp) in an endothermic process?

An endothermic reaction is characterized by:

What is the effect of combining two endothermic reactions in a calorimeter?

In thermodynamics, which term describes the total energy of a system?

If the temperature in a bomb calorimeter raises by 1 K and the heat capacity is 15.5 kJ/K, what is the heat released?

How does an isolated system differ from a closed system?

What is calculated when measuring qp in a calorimeter reacting at constant pressure?

Which of the following best describes a state variable in a gas?

Which of the following is NOT a function of calorimetry?

The first law of thermodynamics is essentially a statement of the conservation of:

What is true about the relationship between qv and qp?

If the internal energy of a system increases, what must happen to its surroundings?

In the energy balance of an endothermic reaction, what must occur to maintain constant pressure?

Which term describes the heat absorbed or released during a reaction at constant pressure?

What does the symbol ∆rH represent in a chemical reaction?

In which scenario is the enthalpy change (∆rH) of a reaction positive?

What is the enthalpy change for the reaction: C (s) + O2 (g) → CO2 (g)?

Which factor does not affect the value of enthalpy change, ∆rH?

When calculating ∆rH using Hess's law, what must be true about the final reaction?

What happens to the enthalpy change (∆rH) when a reaction is reversed?

If the enthalpy of the products is higher than that of the reactants, this indicates a:

For the reaction CO (g) + 1/2 O2 (g) → CO2 (g), what is the value of ∆rH?

What does it mean if a reaction has a negative ∆rH and a positive ∆S?

Which formula correctly represents the calculation of enthalpy change?

Combustion of a substance typically results in which sign of ∆rH?

If the enthalpy change for a certain reaction is zero, what can be inferred about the reaction?

What is the correct interpretation of Hess's law in relation to enthalpy?

In an endothermic reaction, if ∆H is greater than the energy changes of the surroundings, what will happen?

What is the standard enthalpy of combustion for one mole of butane?

Which of the following statements best describes the standard enthalpy of formation?

What does a negative value of ∆cH⁰ indicate about a combustion reaction?

If the enthalpy of combustion of glucose is -2802.0 kJ/mol, what does this imply?

Which equation correctly illustrates the relationship between standard enthalpies of different routes leading to the same product?

Which is a common trap when interpreting enthalpy change values?

What is the significance of the term 'standard state' in thermochemistry?

In the combustion of benzene, how much energy is liberated per mole?

Which of the following reactions generally indicates a decrease in enthalpy?

What is the bond enthalpy of a C-H bond in methane if the total enthalpy change for the breaking of all bonds is +1665 kJ/mol?

How is the standard enthalpy of a reaction related to bond enthalpies?

What is the correct expression for calculating the enthalpy change of a reaction using Kirchhoff's equation?

What is the Gibbs free energy equation?

If a reaction has a negative ∆G, what can be concluded about its spontaneity?

Under what condition is a reaction with positive ∆H and positive ∆S spontaneous?

Which of the following statements about spontaneous processes is true?

Which term describes the measure of disorder in a system?

What does a positive value of ∆G imply for a reaction?

When considering spontaneity, which factor directly influences Gibbs free energy the most?

Which pair of thermodynamic quantities must be evaluated to determine spontaneity?

Which scenario would likely favor the spontaneity of a reaction?

What role does temperature play in reactions that are both endothermic and result in increased entropy?

Which thermodynamic principle asserts that entropy of an isolated system tends to increase over time?

What happens to the spontaneity of a reaction as temperature increases if both enthalpy and entropy are positive?

Which of the following best describes a reaction at equilibrium considering Gibbs energy?

What does the term 'spontaneous' signify in a chemical reaction context?

What does a negative Gibbs free energy change (∆G) indicate about a reaction?

Which of the following equations relates Gibbs free energy change to the equilibrium constant?

At equilibrium, what is the value of ∆G for a reversible reaction?

How does an increase in temperature typically affect the Gibbs free energy for an endothermic reaction?

In a reaction where both ∆H and ∆S are negative, under what condition is the reaction spontaneous?

Which factor does NOT affect the Gibbs free energy change of a reaction?

If ∆G > 0 for a reaction under standard conditions, what can be concluded?

A reaction's equilibrium constant decreases as the temperature increases. Which statement is true about the reaction?

For a reaction characterized by ∆H > 0 and ∆S > 0, when will the reaction be spontaneous?

If the standard Gibbs free energy change of a reaction is given as ∆Gₐ = -RT ln K, what can be inferred about the formation of products?

Consider a reversible reaction at equilibrium. If the concentration of products is increased, how does this affect ∆G?

Which of the following statements is valid regarding ∆G and reaction spontaneity?

In thermodynamics, what does the term 'spontaneity' refer to?

If a reaction has ∆H < 0 and ∆S < 0, under what temperature ranges will the reaction be spontaneous?

What is the significance of a reaction where ∆G = 0?