Sublimation

Question 1 What is sublimation.

Question 2 Define sublimate.

Question 3 Define sublime.

Question 4 Give few examples of substances that undergoes sublimation ?

Question 5 Why naphthalene balls kept in stored clothes in our homes disappear over a period of time ?

Question 6 How does applying pressure help in the liquefaction of a gas ?

Question 7 What is the effect of pressure on change in state of matter?

Question 8 What is solid carbon dioxide?

Question 9 Why solid carbon dioxide is called dry ice ?

Sublimation

The Changing of a solid directly into vapours on heating and of vapours into solid on cooling is called as sublimation.

The solid substance which undergoes sublimation is called sublime.

The solid obtained by cooling the vapours of the solid called a sublimate.

For Example :camphor, Iodine, Ammonium Chloride, Naphthalene etc.

Effect of Change of Pressure

The physical state of matter can be changed by increasing or decreasing the pressure. When a high pressure is applied to a gas, it gets compressed and when we lower its temperature, it gets liquified. Gases can be liquified by compression and cooling.

For Example: Solid carbon dioxide is stored under high pressure. This is because on decreasing the pressure on solid carbon dioxide, it gets converted directly into carbon dioxide gas.