According to the second law of thermodynamics which of the f

According to the second law of thermodynamics, which of the following is true? The decrease in entropy associated with life must be compensated for by increased entropy in the environment in which life exists. All reactions produce some heat. The total amount of energy in the universe is constant. Energy conversions increase the order in the universe. The entropy of the universe is constantly decreasing.

Solution

Ans. Correct option. A. The entropy associated with life decreases, for example thousands of amino acids are joined together with peptide bond, and go through various levels of organization to forms a perfectly ordered enzyme or protein. This decrease in entropy of the living system causes, in turn, is compensated by an increase in the entropy of the surrounding (the environment)- the living organisms break down numerous complex molecules into simpler one and relase them into the surrounding. For example- 1 mol glucose is broken into 6 mol each of CO2 and water and released into the surrounding, thus, resulting an increase in entropy of the surroundings.

Various forms of second law of thermodynamics, with respect to entropy can be stated as follow-

“Any process either increases the entropy of the universe - or leaves it unchanged. Entropy is constant only in reversible processes which occur in equilibrium. All natural processes are irreversible.”

“All natural processes tend toward increasing disorder. And although energy is conserved, its availability is decreased.”

“Nature proceeds from the simple to the complex, from the orderly to the disorderly, from low entropy to high entropy.”

“The entropy of a system is proportional to the logarithm of the probability of that particular configuration of the system occurring. The more highly ordered the configuration of a system, the less likely it is to occur naturally - hence the lower its entropy.”

Option. B. Incorrect. Many reactions are endothermic, i.e. absorb heat. For example, reaction between NH4NO3 + H2O in a cool pack (ice pack) is an endothermic reaction that makes them cool when activated.

Option. C. Incorrect. The statement is true but it’s the first law of thermodynamics. The first law states that “energy can neither be created, nor be destroyed, but can be transformed from one to another form”- so, the total energy of the universe remains constant.

Option. D. Incorrect. Energy conversions, on general for all natural processes, decrease the order (thus, makes it more dis-ordered or increases entropy of the universe) of the universe.

Option. E. Incorrect. The entropy of the universe is constantly increasing.