Question

Identify in each of the following processes whether the entropy of the system decreases or increases:

Salt crystals are dissolved in water

Water condenses on a window in the cool evening

During replication, individual nucleotide bases are combined to form DNA

After exams, you throw your notes into air in a fit of joy

Answer 1

Entropy is measure of disorder in molecules or system. Mire the disorder more will be entropy. In gaseous state disorder more compare to liquid and solid. So entropy is more in gaseous state. Similarly entropy in liquid state is more compared to solid state.

Salt crystals are dissolved in water. Here solid becomes liquid. Entropy increases.

Water condensation. It means water vapours converted into liquid. Entropy decrease.

In replication, disorder decreases so entropy decreases.

In last example disorder increases so entropy also increases.