Question

0/1.5 pts Question 12 Which of the following statement is true? The Second aw of thermodynamics predicts a spontaneous reaction if the entropy of the system increases The First law of thermodynamics allows pred ctlon of spontaneous changes The Third law of thermodynamics states the entropy of any crystal at 0 K is zero to stated fne entropy funiverse wil only Te Second iicthe modvna increate over me

Answer 1

1. Correct Statement

The second law of thermodynamics predicts a spontaneous reaction if the entropy of the system increases.

Explanation:

First of all, let us know what is spontaneous process. A process which occurs without any outside intervention is said to be spontaneous. The process may take place either by itself or by some initiation but no “external” driving force is required. Otherwise, it is said to be a non-spontaneous process. The determining factors for spontaneity of a reaction are the enthalpy and entropy changes that occur for the system. Thus the free energy change of a reaction is a mathematical combination of the enthalpy change and the entropy changes. The second law of thermodynamics states that the entropy of any isolated system always increases. Isolated systems spontaneously evolve towards thermal equilibrium—the state of maximum entropy of the system. Thus it can be said that all spontaneous changes cause an increase in the entropy of the universe.

The First law of thermodynamics also known as Law of Conservation of Energy does not predict spontaneous changes but it states that energy can neither be created nor destroyed; energy can only be transferred or changed from one form to another.

2. Correct Statement:

The second law of thermodynamics states the entropy of universe will only increase over time.

Explanation:

A measure of the level of disorder of a system is entropy, and it is represented by S. The second law of thermodynamics says that the entropy of any isolated system always increases therefore, the entropy of the universe (the ultimate isolated system) only increases and never decreases. Therefore, Entropy, or the disorganization of the matter in the universe goes up every day.

The third law of thermodynamics states that the absolute entropy of a pure crystalline substance is 0 at 0 K. Therefore, some substances like CO₂ have residual entropy at 0 K because their structure is not perfectly crystalline. As a result only perfect crystals and not all crystals have zero entropy at 0 K.