To create "dry ice," manufacturers compress and cool carbon dioxide gas until it solidifies. Describe what happens to the carbon dioxide molecules as the gas is compressed and cooled.

Explanation:

Temperature is defined as the average kinetic energy of the molecules of a substance. When a substance is cooled, the average kinetic energy of its molecules is reduced tremendously. Thus, the molecules of the substance no longer move at high speeds.

Gases, according to the ideal theory of gas molecules do not associate but are infinitely free and move at very high speeds. However, when cooled, the kinetic energy of these molecules become sufficiently low so as to allow intermolecular association. Secondly, compressing the carbon dioxide gas increases the pressure and decreases its volume. This further makes the carbon dioxide molecules to associate more rapidly. Since dry ice is sublime, CO2 doesn't pass through a liquid state, rather a highly ordered solid-state called dry ice is formed.

trig 15.3 cos