$$$ Quiz $$$

Gases

The tendency of molecules to move toward areas of lower

concentration? (Chapter 14.4)

diffusion

What does KMT stand for?

Kinetic molecular theory

What is the ideal gas law?

PV=nRT

What do each of the variables in the ideal gas law stand for?

pressure, volume, temperature, moles, gas

constant

Can you list/name the 5 assumptions made for KMT?

1) Particles are in constant motion. They possess kinetic energy.2) The actual volume of gas particles is negligible. Particles are

far apart.3) Gas particles do not attract or repel.4) The average kinetic energy of a gas is directly proportional to

the Kelvin temperature of the gas.5) All collisions are elastic.

The theoretical temperature at which molecules stop moving.

Absolute zero, 0oK

What is an elastic collision?

A collision between gas molecules where there is no

loss of kinetic energy (KE)

What happens to the pressure of a gas inside a

container if the temperature of the gas increases?

The pressure increases

What are STP conditions?

0oC or 273 K760 mm Hg or 1.0 atm

What is the formula for Gay-Lussac’s Law?

What is the formula for Charles’ Law?

What is the formula for Boyle’s Law?

What is the formula for the combined gas law?

As the temperature of a fixed volume of gas increases, the

pressure will increase. Which gas law is being described?

Gay-Lussac’s Law

As the volume of gas increases, the pressure decreases in a sample of

gas at fixed temperature. Which gas law is being described?

Boyle’s Law

As the temperature of a fixed pressure of gas decreases, the

volume will increase. Which gas law is being described?

None, it would be Charles’ Law if the volume decreased

True or False. The value for R of 0.0821 L.atm/mol.K is the same

anywhere in the galaxy or for that matter in the universe.

True

You have one mole of gas at 273 K and 1 atm in a balloon. How big must the balloon be?

22.4 L

How many different units of pressure can you name? (1 CD for each one you name up to 6 CD’s)

mm Hg (or inches)pascals (Pa) or kilopascals (kPa)

atmospheres (atm)pounds per square inch (psi)

torrbars

Which temperature scale is the best to use when working with the gas laws?

Kelvin

You have a temperature of a sample of gas at 205 K. What

temperature in oC is this?

-68oC

You have 28 grams of nitrogen gas at 0oC and a pressure of 760 mm of Hg.

What is its volume?

22.4 L

You have 14 grams of nitrogen gas at 0oC and a pressure of 760 mm of Hg.

What is its volume?

11.2 L

You have 28 grams of nitrogen gas at 273 K and a pressure of 0.5 atm.

What is its volume?

44.8 L

You have 14 grams of nitrogen gas at 0oC and a pressure of 380 mm of Hg.

What is its volume?

22.4 L

True or False. Air pressure increases as you go higher in altitude (up to the top of a

mountain).

False

Chemical equations must be balanced to satisfy _____

the law of conservation of mass

What is Avogadro’s number?

6.02 x 1023 particles per mole

The pressure in a gas container is 237 mm Hg. How many atmospheres

(atm) is this?

0.31 atm

If you have 1 mole of a gas at 1.0 atm, what does the ideal gas

law simplify down to.

V = RT

The volume of gas is doubled while the temperature is held constant. How does the gas

pressure change?

Reduced by one half

What is a precipitate?

A solid that forms during a chemical reaction