Absorption/evolution of heat during conversion of a substance from one allotropic form to another is termed as the heat of September 7, 2025 by Admin A. Sublimation B. Fusion C. Transition D. Vaporisation ✅ The correct answer is option C.
One mole of nitrogen at 8 bar and 600 K is contained in a piston-cylinder arrangement. It is brought to 1 bar isothermally against a resisting pressure of 1 bar. The work done (in Joules) by the gas is September 7, 2025 by Admin A. 30554 B. 10373 C. 4988.4 D. 4364.9 ✅ The correct answer is option B.
If heat contents of CH₄, C₂H₄ and C₃H₈ are -17.9, 12.5 and -24.8 kcal/mole respectively, than ΔH for the reaction CH₄(g) + C₂H₄(g) ⇋ C₃H₈(g) will be __________ Kcal. September 7, 2025 by Admin A. -19.4 B. -30.2 C. 55.2 D. -55.2 ✅ The correct answer is option A.
1m³ of an ideal gas at 500 K and 1000 kPa expands reversibly to 5 times its initial volume in an insulated container. If the specific heat capacity (at constant pressure) of the gas is 21 J/mole . K, the final temperature will be September 7, 2025 by Admin A. 35 K B. 174 K C. 274 K D. 154 K ✅ The correct answer is option C.
The extensive properties are September 7, 2025 by Admin A. Volume, mass and number of moles B. Free energy, entropy and enthalpy C. Both A and B D. None of these ✅ The correct answer is option C.
Pick out the undesirable property for a good refrigerant. September 7, 2025 by Admin A. High thermal conductivity B. Low freezing point C. Large latent heat of vaporisation D. High viscosity ✅ The correct answer is option D.
The chemical potential for a pure substance is __________ its partial molal free energy. September 7, 2025 by Admin A. More than B. Less than C. Equal to D. Not related to ✅ The correct answer is option C.
For an ideal gas, the enthalpy September 7, 2025 by Admin A. Increases with rise in pressure B. Decreases with rise in pressure C. Is independent of pressure D. Is a path function ✅ The correct answer is option C.
In case of vapour compression refrigeration system, elevating the evaporator temperature (keeping the condenser temperature constant) results in September 7, 2025 by Admin A. Enhanced COP B. Decreased COP C. No change in the value of COP D. Increased or decreased COP ; depending upon the type of refrigerant ✅ The correct answer is option A.
The value of Joule-Thomson co-efficient, in case where cooling occurs after the throttling process is September 7, 2025 by Admin A. 0 B. ∞ C. +ve D. -ve ✅ The correct answer is option C.