2nd and 3rd Law of Thermodynamics and Entropy MCQs
Thermodynamics is a branch of science that explores the quantitative relationships between energy sources and the interconversion of heat and work. It is governed by four fundamental laws. The zeroth law states that if two systems are each in thermal equilibrium with a third system, they are also in thermal equilibrium with each other. The first law emphasizes the conservation of energy, asserting that the total energy of an isolated system remains constant; energy cannot be created or destroyed, only transformed from one form to another. The second law indicates that the entropy of an isolated system, which is not in equilibrium, will increase over time until it reaches a maximum value. The third law posits that as the temperature of a system approaches absolute zero, its entropy approaches a constant minimum. These principles collectively help determine the viability and direction of various physical and chemical transformations.
What is the ratio of Cp/Cv for gas if the pressure of the gas is proportional to the cube of its temperature and the process is an adiabatic process?
(a) 2
(b) 3/2
(c) 4/3
(d) 5/3
Which of the following processes is used to do maximum work done on the ideal gas that is compressed to half of its initial volume?
(a) isothermal
(b) isochoric
(c) isobaric
(d) adiabatic
A perfect black body has a unique characteristic feature as
(a) a good absorber only
(b) a good radiator
(c) a good absorber and a good radiator
(d) neither a radiator nor an absorber
Chemical dissociation is
(a) exothermic
(b) reversible
(c) endothermic
(d) reversible and endothermic
Which of the following factor affects the heat of reaction based on Kirchhoff equation?
(a) molecularity
(b) temperature
(c) pressure
(d) volume
Which of the following is the largest unit of energy?
(a) electron volt
(b) joule
(c) calorie
(d) erg
Which of the following laws was formulated by Nernst?
(a) First law of thermodynamics
(b) Second law of thermodynamics
(c) Third law of thermodynamics
(d) None of the above
What is a necessary condition for a reaction to be spontaneous at all temperatures?
(a) 𐤃H < 𐤃G
(b) 𐤃G and H should be positive
(c) 𐤃H = 𐤃G = 0
(d) 𐤃G and 𐤃H should be negative
A thermodynamic process where no heat is exchanged with the surroundings is
(a) isothermal
(b) adiabatic
(c) isobaric
(d) isotropic
The coefficient performance of a refrigerator is 5. Calculate the heat rejected to the surrounding if the temperature inside the freezer is -20oC
(a) 11oC
(b) 41oC
(c) 21oC
(d) 31oC
