Question

Identify the following statements as true or false. (Use the drop-down menu and select "True" or "False" for each. You must get all 6 correct.)
1. The entropy of the universe is constant; the energy of the universe decreases towards a minimum.
2. If a reaction is spontaneous, the reverse reaction is non-spontaneous.
3. If a process decreases the randomness of the particles of a system, the entropy of the system decreases.
4. Both ΔS_sys and ΔS_surr must equal zero at equilibrium.
5. All systems become more disordered spontaneously.
6. The boiling of water at 105°C and 1 atm is a spontaneous process.

Answer 1

Ans- (a) False (the second law of thermodynamics, states that the total entropy of any system cannot decrease. The entropy of the whole universe, assumed to be an isolated system, cannot decrease. In fact the entropy of the universe is always increasing)

   (b) False (it is not compulsory)

   (C) False (The definition of entropy is the measure of disorder in a system. By decreasing randomness you have decreased disorder and therefore have decreased energy in system but the energy was transferred to surroundings )

   (d) True (In a thermodynamic system, a "universe" consisting of "surroundings" and "systems" and made up of quantities of matter, its pressure differences, density differences, and temperature differences all tend to equalize over time - simply because equilibrium state has higher probability than any other )

   (e) False ( In chemical thermodynamics, an endergonic reaction (also called an unfavorable reaction or a nonspontaneous reaction) is a chemical reaction in which the standard change in free energy is positive, and energy is absorbed. The total amount of energy is a loss (it takes more energy to start the reaction than what you get out of it) so the total energy is a negative net result.)

   (f) True (A spontaneous process is the time-evolution of a system in which it releases free energy (most often as heat) and moves to a lower, more thermodynamically stable, energy state. In the boiling water , energy is released from the liquid H2O to phase change to the steam )