Particle Model & Pressure Flashcards

All 9 cards in this deck

What causes the pressure of a gas on the walls of its container?

The gas particles collide with the walls; each collision exerts a force, and pressure is that force spread over the area of the wall.

What happens to the mean speed and kinetic energy of gas particles when the gas is heated?

Both increase — the particles move faster and have greater kinetic energy.

Why does the pressure of a fixed mass of gas at constant volume increase when it is heated?

e.g. a sealed can moved from a cold room to a warm room

The particles move faster, so they hit the walls more often and each collision exerts a bigger force — so the pressure inside the can rises.

What is absolute zero?

−273 °C — the lowest possible temperature, at which the particles have no movement (no kinetic energy).

How do you convert a temperature from degrees Celsius to kelvin?

Add 273: temperature (K) = temperature (°C) + 273.

How do you convert a temperature from kelvin to degrees Celsius?

Subtract 273: temperature (°C) = temperature (K) − 273.

What is absolute zero on the kelvin scale?

0 K. The kelvin scale starts at absolute zero.

How does a temperature change of 1 °C compare with a temperature change of 1 K?

They are the same size — a rise of 1 °C is a rise of 1 K.

At constant temperature, what happens to the pressure of a gas when more particles are put into the same volume, and why?

It increases, because there are more particles to collide with the container walls, so collisions happen more often.