Chem Quiz State of Matter Review

Why is atmospheric pressure higher at a lower elevation?

When its lower there is more space for molecules to move therefore the pressure is higher.

What is a vacuum?

A space with no pressure so no particles move. Like pace

What does it mean for a collision to be elastic?

An elastic collision is a type of collision where both momentum and kinetic energy are conserved. This means that after the collision, the total kinetic energy of the colliding bodies is the same as it was before the collision.

State two ways for pressure to be decreased.

• Go higher up

• Use a pump (of some sort) to remove the air

What are the three pars of the kinetic molecular theory? State two ways that the theory is incorrect.

1. Gases are made up of particles called atoms or molecules.

2. Gases are in constant random motion

3. During collisions, we assume all collisions are elastic.

   1 and 3 are incorrect.

What causes pressure?

Molecules moving together and colliding and being close together.

At what temperature does absolute zero occur? What is the true temperature?

0 Kelvin - -273.

What is the standard temperature?

0 C

What is standard Pressure?

101.3 KPA = 73 degrees = 1 atm

State one way in which gas and liquids are similar.

Both can flow and take the shape of their containers.

What makes liquids more dense than gases?

Liquids have higher attraction and less energy.

Why is evaporating a cooling process?

Molecules rise to the surface to escape which cools them off. Molecules that escape and are left over eventually form equilibrium.

What vapor causes pressure?

When water is vaporizing in a container and the molecules bump into the containers walls.

When does a boiling point occur?

A boiling point occurs when a liquid's vapor pressure equals the atmospheric pressure.

What are two ways boiling can be started

By adding heat or decreasing pressure.

What is gas pressure

Collisions of a gas on a surface.