Why does the temperature of a substance remain constant during its melting point or boiling point?

Due to Screening/shielding effect.

In steam distillation, the organic liquid starts to boil when the sum of vapour pressure due to the organic liquid (p1) and the vapour pressure due to water (p2) becomes...

During a change of state, the temperature remains constant. This is because all the heat supplied to increase the temperature is utilised (as latent heat) in changing the state by...

This is because the overall cell reaction does not involve any ion in the solution whose concentration changes during its life time

(a) The molecules in covalent compounds are held by weak van der Waa s forces, hence they have low melting points and boiling points as compared to ionic compounds. (b) Carboxylic...

(D) Combustion of Liquefied Petroleum Gas (LPG)

(i) Large amount of heatenergy is required to break the inter-ionic attractive forces.  (ii) A thin but strong layer of aluminium oxide is formed on its surface which protects aluminium atoms...

(a) speed (d) magnitude of acceleration. Explanation:  On a curved path, instantaneous direction of movement changes continuously. So, a vector can not remain constant on a curved path because it has both magnitude and direction. In the...

(b) gradually decrease

(a) speed (d) magnitude of acceleration. Explanation:  On a curved path, instantaneous direction of movement changes continuously. So, a vector can not remain constant on a curved path because it has both magnitude...