Which of the following changes are not reversible Select one: a. Dehydration b. Melting c. Decomposition d. Hydration

d. Decomposition

Explanation:

Reversible changes -

As the name suggests the the changes which can be reversed back to the original compound, is referred to as reversible changes.

All the physical changes are reversible in nature.

For example,

Melting of ice, as the ice is melted from solid to liquid form, the liquid can again be converted back to solid, by reducing the temperature.

The process of hydration and dehydration are exactly opposite to each other, As hydration refers to the addition of water on to the system, where as dehydration refers to the process of removing water from the system,

Hence, the changes are reversible in nature.

Decomposition is the process of break down of the chemical species into two or more species.

The species can not be further merged back to get back the original compound, hence is not a reversible change.