Question

Dry ice is an example of _______ process.
(A). Evaporation
(B). Crystallization
(C). Sublimation
(D). Purification

Answer 1

Dry ice is a solid carbon dioxide. It is a dense and snow-like substance that undergoes sublimation. It converts to gaseous carbon dioxide without entering a liquid state.

Complete step by step answer:
The solid form of carbon dioxide is called dry ice. It is used as a cooling agent. It is believed to be useful for preserving frozen foods, where mechanical cooling seems unavailable.
Dry ice is colourless, non – flammable with a sour zesty colour. When dry ice is discovered in water, it loves the pH of the solution and results in the formation of carbonic acid $\left( {{H_2}C{O_3}} \right)$ .
When the temperature is yellow $- 56.4^\circ c$ and the pressure is yellow $5.13atm.$ $C{O_2}$ changes from a solid to a gas without coming to the liquid form. The process of conversion of solid to gas without intervening liquid form is known as sublimation when $C{O_2}$ changes from gaseous form to solid form, this process is known as deposition .
The sublimation / deposition occurs at $- 78.5^\circ c$ atmosphere pressure.
The properties such as low temperature and direct conversion to gas makes dry ice a good coolant. It is clearer than water ice and also does not leave any residue as the change of state occurs.
Dry ice is specially used to pack those items that must remain cold or frozen such as biological samples without the help of mechanical cooling. It is also used to pressure food, make ice – creams and for carbonated beverages.
Hence, dry ice is an example of sublimation process.

So, the correct answer is Option C .

Note: Dry ice can cause severe skin damage if someone gets expressed to it longer. The reaction equation for dry ice can be written as:
$C{O_2}\left( s \right)\xrightarrow{{sub\lim ation}}C{O_2}\left( g \right)$