Question

In a physics classroom demonstration, an instructor inflates a balloon by mouth and then cools it in liquid nitrogen. When cold, the shrunken balloon has a small amount of light blue liquid in it, as well as some snow-like crystals. As it warms up, the liquid boils, and part of the crystals sublimate, with some crystals lingering for a while and then producing a liquid. Identify the blue liquid and the two solids in the cold balloon. Justify your identifications using data from Table.

Short answer

The blue liquid in the balloon is oxygen, and the two solids are carbon dioxide and water.

Step-by-step solution

Explain the scenario

The instructor inflates the balloon by using his mouth. So, oxygen can be present in it. When it is cooled by liquid nitrogen, we can observe some particles inside it. There was a blue liquid as well as two types of snow-like crystals. When this liquid boils, one of the crystals sublimes, and the other melts.

At the boiling of the liquid, one of the crystals turns into vapor and the other one turns into liquid. Here, you have to identify the liquid by comparing the boiling point and melting point of this liquid with that of nitrogen.

Identify the particles present in the balloon

The blue liquid present in the balloon is oxygen because, from the table, you can understand that the melting point of oxygen is lower than the boiling point of nitrogen. So, by cooling nitrogen, oxygen will transform into liquid form.

The sublimed crystal is carbon dioxide. because it doesn’t exist in the liquid phase at atmospheric pressure and it will directly transform into a gas. The crystal which turns to liquid is water because its melting point is higher than the boiling point of water. It just transforms into liquid.

So, the liquid in the balloon is oxygen, and the crystals are carbon dioxide and water.