Question

Which of the following changes leads to an increase in entropy of the system?

The evaporation of water from a puddle

The freezing of water into an ice cube

The formation of starch from glucose molecules

The digestion of protein into amino acids

None of these

Answer 1

Answer-1)

Entropy is the degree of randomness or dissordness of a system. More the randomness, more the entropy.

1) The evaporation of water from the puddle- When solid water(ice) melts into liquid water, the entropy of the system increases as the degree of randomness increases that is the the number of ions will increase thus they can move freely in the water. When this liquid water evaporates, there much higher degree of randomness as the gas molecules are more far away from each other leading to increase in entropy. Higher the degree of randomness, higher the entropy.

Incorrect:

2) The freezing of water into ice cube means making the molecules more structured and ordered thus reducing the randomness thus decreasing the entropy.So incorrect option.

3) Starch is a highly branched chain of glucose molecules. So more glucose molecules linked to each other decreases the randomness as compared to glucose molecule. So entropy decreases thus incorrect option.

4) Amino acids are a chain of proteins linked to each other thus leading to decrease in randomness as compared to a protein. So digestion of protein into amino acids will lead to a decrease in the entropy.

5) option 1 is correct.