Which of the following process/ processes release heat? (i) Condensation (ii) Vaporisation (iii) Freezing (iv) Melting Correct option is :

Which one of the following processes is NOT useful for purification of solid impurities?

The evaporation of water increases under the following conditions :

Consider the following statements: 1. Addition of salt to pure water increase the boiling point of water and decreases the freezing point of water. 2. When methyl alcohol is added to water boiling po…

Consider the following statements about mixture : 1. A substance can be separated into other kinds of matter by any physical process. 2. Dissolved sodium chloride can be separated from water by the p…

Refining of petroleum is carried out using which one of the following techniques?