F4 Fun With Liquid Nitrogen

Background

Heating and cooling substance may bring about one or more physical changes in a substance. Regardless of the change, at the particle level, changes in their motion invariably take place which at times can be dramatically demonstrated.

Resources:
M4 Chemistry Matter II: State and Energy. PowerPoint slides on the relationship between state of matter and energy content of particles in a sample of the matter.

Discrepant Event

The video below shows three different demonstrations looking at the effect of cooling a squash ball, a rose and a small balloon filled with air using liquid nitrogen. Watch the video to see what happens.

And the questions are:

  1. Why did the squash ball and the rose shatter like glass?
  2. Why did the balloon deflate when introduced into liquid nitrogen and then spontaneously inflate when taken out?

Concepts involved:

  • cooling, heating, heat, energy/heat transfer/exchange, motion of particles, pressure, temperature.

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