Question

What is the process of phase change going on the external surface of the cold finger during sublimation experiment and what is the role of the ice cold water in the cold finger?

Answer 1

Cold finger is the instrument used in sublimation experiment to generate very low temperatures

sublimation is the process of converting solid into gas/vapour state directly without liquid phase.Some material undergoes sublimation process during seperation from a mixture of compounds.

Cold finger consists of continoues inflow and out flow of coolant(ice cold water) which maintains low temperatures onthe surfaces when ever the sublimed substance coming contact with cold external surface it undergoes deposition on the external surface by crystallization or some other process due to low temperature.Here the role of ice cold water is to act as coolant for maintaining low temperature surfaces .