Sublimation and Phase Changes

The video tutorial explains the concept of sublimation, where a solid transforms directly into a gas without becoming a liquid first. It uses the example of naphthalene balls, which reduce in size when exposed to air due to sublimation. The tutorial also describes an experiment with ammonium chloride, demonstrating how it sublimates when heated. The vapors cool and revert to a solid state on a glass surface, illustrating the sublimation process. The video concludes by reinforcing the understanding of sublimation through these practical examples.

What happens to naphthalene balls when they are exposed to air for some days?

• They reduce in size.

• They increase in size.

• They remain unchanged.

• They melt into a liquid.

What is the process called when a solid transforms directly into a gas?

• Evaporation

• Condensation

• Sublimation

• Freezing

In sublimation, what does a solid transform into?

• Another solid

• Plasma

• Gas

• Liquid

What is used in the experiment to demonstrate sublimation?

• Potassium chloride

• Ammonium chloride

• Calcium chloride

• Sodium chloride

What is placed on the china dish in the sublimation experiment?

• A petri dish

• A beaker

• A glass funnel

• A test tube

What happens to the vapors of ammonium chloride when they cool down?

• They turn into a liquid.

• They remain as vapors.

• They disappear.

• They transform into a solid.