Question

Which of the assumptions of the kinetic-molecular theory best explains the observation that a balloon collapses when exposed to liquid nitrogen (which is much colder than a cold winter day!!)? Which of the assumptions of the kinetic-molecular theory best explains the observation that a balloon collapses when exposed to liquid nitrogen (which is much colder than a cold winter day!!)? Gas molecules move at random with no attractive forces between them. The amount of space occupied by a gas is much greater than the space occupied by the actual gas molecules. Collisions with the walls of the container or with other molecules are elastic. The velocity of gas molecules is proportional to their Kelvin temperature. In collisions with the walls of the container or with other molecules, energy is conserved.

Answer 1

The answer is; The velocity of gas molecules is proportional to their Kelvin temperature

The higher the temperatures of a gas, the higher the kinetic energy of the gas molecules. This means that the molecules are colliding with each other at a higher frequency and with the walls of the balloon. This causes the distance between molecules to increase. When the temperatures are lowered, the opposite happens. The molecules lose kinetic energy and come close together hence reducing the volume of the gas.

Answer 2

The velocity of gas molecules is proportional to their Kelvin temperature.

Step-by-step explanation:

The average velocity of the gas molecules is directly proportional to the Kelvin temperature which is given by:

v =
`\sqrt{(3RT)/(M) }`

where v, R, T and M are the velocity of the gas, R is the universal gas constant, T is the absolute temperature in Kelvin and M is the molar mass of the gas.

As the temperature is lowered the velocity of the gas particles simultaneously lowers and the balloon collapses.