Thermodynamics practice · Mixed difficulty

Option C (Quantity which depends only on the state of the system) is correct because a thermodynamic quantity is a state function, meaning its value depends only on the initial and final states of the system, not the path taken.

Option C ($95.73\,J\,{K^{ - 1}}$) is correct because it correctly calculates the entropy change for an isothermal reversible expansion using the formula $\Delta S = nR \ln{\frac{V_2}{V_1}}$.

Option A (The principle of conservation of energy) is correct because the law of Lavoisier and Laplace states that the energy change accompanying a reaction is equal in magnitude and opposite in sign to the energy change accompanying the reverse reaction, which is a direct consequence of the conservation of energy.

Option C ($(q_2-q_1)$) is correct because the enthalpy of ionization is the difference between the heat released during the neutralization of a strong acid and the heat released during the neutralization of the weak acid.

Option C (800 K to 801 K) is correct because the reaction changes from spontaneous to non-spontaneous when $\Delta G$ changes sign, which occurs around $T = \frac{{\Delta H}}{{\Delta S}}$.

Option C (Remain constant) is correct because specific heat is an intensive property and does not depend on the amount of substance or volume.

Option A (-13.7 kcal) is correct because the heat of formation of water from its ions is negative, indicating an exothermic process.

Option B ($100\mathrm{J mo}{\mathrm{l}^{ - 1}}{\mathrm{K}^{ - 1}}$) is correct because the entropy change is calculated using ∆S = ∆H/T for a phase transition at constant temperature.

Option C (373.4 K) is correct because it is the temperature at which the Gibbs free energy change (∆G) is zero, calculated using the formula ∆G = ∆H - T∆S.

Option A (The standard enthalpy of an overall reaction is the sum of the enthalpy changes in individual reactions) is correct because it accurately describes Hess's Law.

Argon (Ar) is the correct answer because it is a monatomic gas, and for monatomic gases, $C_p - C_v = R$. The given values are close to R when converted to appropriate units.

Option D ($-1.13 \text{ kJ}$) is correct because it is calculated by subtracting the heat of combustion of red phosphorus from the heat of combustion of yellow phosphorus.

Option C is the correct definition of heat of solution because it specifies the heat change when one mole of solute dissolves in excess solvent until further dilution causes no heat change.

Option B (Heat of the gas is lost as work is done by the gas) is correct because during expansion, the gas performs work, which requires energy, leading to a decrease in the gas's internal energy and thus cooling.

Option B (Is always positive) is correct because bond energy is defined as the energy required to break a bond, which is always an endothermic process.

Option A ($\Delta U$) is correct because heat of reaction at constant volume is equal to the change in internal energy.

Option A (Enthalpy of mixing is zero) is correct because for an ideal solution, there are no enthalpy changes upon mixing, indicating no heat is absorbed or released.

Option A is correct because the standard free energy change is related to the equilibrium constant by the equation ΔG° = -2.303RTlogK.

Option A (20 cal) is correct because the change in internal energy is calculated by subtracting the work done by the system from the heat added to the system.

Option A is correct because entropy is a state function and its value depends on the amount of substance, making it an extensive property.

Option D (0.24 K) is correct because it is the increase in temperature calculated using the formula relating heat supplied, mass, specific heat capacity, and temperature change.

Option C is correct. Ammonium nitrate absorbs the maximum amount of heat because it has the largest positive $\Delta H$ value, indicating an endothermic process where heat is absorbed from the surroundings.

Option A is correct because the formation of gaseous oxides of nitrogen requires breaking the strong triple bond in the nitrogen molecule, which requires energy.

Option D is correct because an ideal crystal has less entropy and more order than a real crystal due to the absence of defects.

Option B (Q=0) is correct because an adiabatic process is defined as a process in which there is no heat exchange between the system and the surroundings.

Option A (ΔU=4170 J; ΔH=1 kcal) is correct because it involves calculating the change in internal energy and enthalpy using the given heat added and volume change at constant pressure.

Option A ($2.01 \times {10^3}\mathrm{J}$) is correct because it is the maximum work done calculated using the isothermal reversible expansion formula.

Option D ($- 19.4\mathrm{kcal mo}{\mathrm{l}^{ - 1}}$) is correct because it represents the enthalpy change calculated by subtracting the sum of the enthalpies of the reactants from the enthalpy of the product.

Option B ($L{T^{ - 1}}$) is correct because entropy change is defined as heat absorbed divided by temperature.

The question is incomplete and does not provide enough information to determine the change in internal energy (ΔU). It seems there is a typo and the correct answer cannot be determined with the given information.