Specific _____________ does not change during phase change at constant temperature and pressure?
(A) Entropy
(B) Gibbs energy
(C) Internal energy
(D) Enthalpy
A change in state involving a decrease in entropy can be spontaneous, only if ____________________?
(A) It is exothermic
(B) It is isenthalpic
(C) It takes place isothermally
(D) It takes place at constant volume
“Law of corresponding states” says that___________________?
(A) Two different gases behave similarly, if their reduced properties (i.e. P, V and T) are same
(B) The surface of separation (i. e. the meniscus) between liquid and vapour phase disappears at the critical temperature
(C) No gas can be liquefied above the critical temperature, howsoever high the pressure may be.
(D) The molar heat of energy of gas at constant volume should be nearly constant (about 3 calories)
At 60° C, vapour pressure of methanol and water are 84.562 kPa and 19.953 kPa respectively. An aqueous solution of methanol at 60° C exerts a pressure of 39.223 kPa; the liquid phase and vapour phase mole fractions of methanol are 0.1686 and 0.5714 respectively. Activity co-efficient of methanol is__________________?
(A) 1.572
(B) 1.9398
(C) 3.389
(D) 4.238
The compressibility factor of a gas is given by (where, V1 = actual volume of the gas V2 = gas volume predicted by ideal gas law)____________________?
(A) V1/V2
(B) V2/V1
(C) V1 – V2
(D) V1.V2
The freezing point of a liquid decreases when the pressure is increased, if the liquid ____________ while freezing?
(A) Contracts
(B) Expands
(C) Does not change in volume
(D) Either (A),
The number of degrees of freedom for an azeotropic mixture in a two component vapourliquid equilibria is/are__________________?
(A) Zero
(B) One
(C) Two
(D) Three
At the critical point of a substance____________?
(A) The surface tension vanishes
(B) Liquid and vapour have the same density
(C) There is no distinction between liquid and vapour phases
(D) All A,
The amount of heat required to decompose a compound into its elements is _____________ the heat of formation of that compound from its elements?
(A) Less than
(B) More than
(C) Same as
(D) Not related to
Gases are cooled in Joule-Thomson expansion, when it is _____________ inversion temperature?
(A) Below
(B) At
(C) Above
(D) Either