Multiple Choice Questions on Thermodynamics
1- The compressibility factor Z for an ideal gas is
(A) Zero
(B) Greater than one
(C) Less than one
(D) Equal to one
2- The fraction of total molecules which is ionised in a solution of an electrolyte is known as _______
(A) Degree of dissociation
(B) Dissociation constant
(C) Electrolyte constant
(D) Mole fraction of the electrolyte
3- The standard entropy S°, of a substance is _______
(A) Its entropy at 25 K and 1 atm pressure
(B) Its entropy at 0 K and 1 atm pressure
(C) Its entropy at 0° C and 1 atm pressure
(D) Its entropy at 25°C and 1 atm pressure
4- The cycle of process which occurs under reversible conditions is referred to as
(A) Carnot cycle
(B) Cyclic process
(C) Closed process
(D) Reversible cycle
5- Entropy is a measure of _______ of the molecules of the system
(A) Randomness
(B) Zig-zag motion
(C) Velocity
(D) Concentration
6- The change in free energy is a measure of
(A) Net change in internal energy
(B) Net change in entropy
(C) Net work done
(D) Net change in enthalpy
7- When water is cooled to ice, its entropy
(A) Increases
(B) Remains the same
(C) Decreases
(D) Becomes zero
8- The correct unit for entropy is
(A) KJ mol
(B) KJ mol-1
(C) JK-1 mol
(D) JK-1 mol-1
9- In a reaction, the threshold energy is equal to _______
(A) Activation energy + Normal energy of reactants
(B) Activation energy – Norma energy of reactions
(C) Activation energy
(D) Normal energy of reactions
10- Which one out of the following is not a state function ?
(A) Work function
(B) Work done
(C) Entropy
(D) Free energy
11- The value of thermodynamic probability (W) of a pure crystalline substance at absolute zero of temperature will be
(A) zero
(B) one
(C) infinity
(D) negative
12- The Joule-Thomson coefficient for Helium and hydrogen gases is
(A) Negative
(B) Positive
(C) Zero
(D) Positive at high temperature and zero at low temperature
ANSWERS:
1-(D), 2-(A), 3-(D), 4-(A), 5-(A), 6-(C), 7-(C), 8-(D), 9-(A), 10-(B), 11-(B), 12-(A)