Iodine Phase Changes and Observations

The video demonstrates the sublimation of iodine, where solid iodine is heated on a hotplate, producing a purple gas. This process bypasses the liquid phase, transitioning directly from solid to gas. The iodine gas can be captured by placing a cold watch glass with ice over the beaker, causing the gas to revert to solid crystals. The video concludes with a visual of the iodine crystals formed under the watch glass.

What is observed when solid iodine is added to hot sand?

• The iodine remains unchanged.

• The iodine melts into a liquid.

• A purple gas is produced.

• A blue liquid forms.

What phase change occurs during the sublimation of iodine?

• Solid to liquid

• Gas to liquid

• Liquid to gas

• Solid to gas

How can iodine gas be captured and converted back to a solid?

• By cooling it with a hot plate

• By adding more iodine

• By using a watch glass with ice

• By heating it further

What happens to iodine gas when it comes into contact with a cold surface?

• It turns into solid crystals.

• It evaporates completely.

• It turns into a liquid.

• It remains as a gas.

What is the appearance of iodine crystals formed on the watch glass?

• They are invisible.

• They are purple gas bubbles.

• They are liquid droplets.

• They are dangling solid crystals.

What is the role of the watch glass in the experiment?

• To heat the iodine

• To capture and cool the iodine gas

• To stir the iodine

• To measure the temperature

What is the final observation made in the video?

• The iodine remains as a solid.

• The iodine gas turns into a liquid.

• The iodine gas escapes without any change.

• The iodine crystals form on the watch glass.