4 - States of Matter/Gas Laws

What is the formula for converting kPa to atm?

kPa/101.3 kPa

According to the kinetic theory, collisions between molecules in a gas

are perfectly elastic

The particles in a gas are best described as

small, hard, fast-moving spheres with insignificant volumes that travel in straight lines between collisions.

Standard conditions when working with gases are defined as

0 degrees Celsius and 101.3 kPa

How does the atmospheric pressure at altitudes below sea level compare with atmospheric pressure at sea level?

The atmospheric pressure below sea level is higher.

What causes gas pressure in a container such as a helium balloon?

the simultaneous collisions of fast-moving particles with the container

What is the relationship between atmospheric pressure and altitude?

inverse

As altitude increases, atmospheric pressure

decreases

The pressure of a gas in a container is 30.4 kPa. This is equivalent to

0.300 atm

The temperature at which the motion of particles theoretically ceases is ____.

0 K (absolute zero)

With which temperature scale is temperature directly proportional to average kinetic energy?

Kelvin

Which are the first particles to evaporate from a liquid?

particles with the highest kinetic energy

In a dynamic equilibrium between the liquid state and the gas state, what is true about the rate of evaporation?

it is equal to the rate of condensation

Water could be made to boil at 105°C instead of 100°C by

increasing the external pressure

What best describes the motion of the particles in a piece of steel?

all are moving

Most solids

are dense and difficult to compress

The physical properties of liquids are determined by

the interplay between the disruptive motions of particles in a liquid and the attractions among the particles.

The escape of molecules from the surface of a liquid is known as ____.

evaporation

The direct change of a substance from a solid to a gas is called ____.

sublimation

The labeled point in Figure 1 at which sublimation can occur is

E

In Figure 1, which sections represent solid, liquid, and gas?

1 = solid, 2 = liquid, 3 = gas

Refer to Figure 2:  the combination of temperature and pressure at which carbon can exist simultaneously as solid, liquid, and gas (triple point) is about

3950 K and 10,000 kPa

The substance is only a gas at point ____ on the diagram.

5

Boiling is occurring at point ____ on the diagram.

4

Why is a gas easier to compress than a liquid or a solid?

The volume of a gas’s particles is small compared to the overall volume of the gas.

Why does the pressure inside a container of gas increase if more gas is added to the container?

There is an increase in the number of collisions between particles and the walls of the container.

If the volume of a container of gas is reduced, what will happen to the pressure inside the container?

the pressure will increase

Which of these changes would cause a decrease in the pressure of a contained gas?

The volume of the container is increased.

The volume of a gas is doubled while the temperature is held constant. How does the gas pressure change?

it is reduced by one half

The volume of a gas is reduced from 4.0 L to 0.5 L while the temperature is held constant. How does the gas pressure change?

it increases by a factor of eight

Boyle's law states that the ____.

volume of a gas varies inversely with pressure when temperature is constant

Charles's law states that the ____.

volume of a gas is directly proportional to its temperature in kelvins when pressure is constant

Gay-Lussac’s Law states that the ____

pressure of a gas is directly proportional to the Kelvin temperature when volume is constant

What is the formula for Boyle’s Law?

P1 x V1 = P2 x V2

What is the formula for Charles’ Law?

V1/T1 = V2/T2

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

P1/T1 = P2/T2

What is the formula for the Combined Gas Law?

(P1 x V1)/T1 = (P2 x V2)/T2

If a balloon is heated, what happens to the volume of the air in the balloon if the pressure is constant?

it increases

As the temperature of a fixed volume of a gas increases, the pressure will ____.

increase

If a sealed syringe is plunged into cold water, in which direction will the syringe piston slide?

in

A gas occupies a volume of 2.4 L at 14.1 kPa. What volume will the gas occupy at 84.6 kPa?

0.40 L

If a sealed syringe is heated, in which direction will the syringe plunger  move?

out

A sample of gas occupies 17 mL at –112 degrees Celsius. Assuming the pressure is held constant, what volume does the sample occupy at 70 degrees Celsius?

36mL

How do you convert temperature in Celsius to Kelvin?

Add 273.15

How do you find V2 in a problem using Charles’s Law?

V2 = V1 x T2/T1

How do you find V2 in a problem using Boyle’s Law?

V2 = (P1 x V1)/P2

In general, for a gas at a constant volume, the

pressure of the gas is directly proportional to its temperature in kelvins.

What does the combined Gas law relate to?

temperature, pressure, and volume

If a balloon containing 3000 L of gas at 39 degrees Celsius and 99 kPa rises to an altitude where the pressure is 45.5 kPa and the temperature is 16 degrees Celsius, the volume of the balloon under these new conditions would be calculated using the following conversion factor ratios (units not shown): ____.

3000 L x (99/45.5) x (289/312)

How do you find V2 in a problem using the combined gas law?

V2 = V1 x (P1/P2) x (T2/T1)

If the volume of a container of air is reduced by one-half, what happens to the pressure within the container?

it is doubled

What is a barometer

A device used to measure atmospheric pressure

Average atmospheric pressure is

101.3 kPa

A vacuum is

An empty space with no particles and no pressure

Do attractive or repulsive forces exist between gas particles?

No

What is an elastic collision

one where kinetic energy is transferred from one particle to another with no overall loss of kinetic energy

What is the formula for finding volume of a gas at STP?

V = nRT/P

What is the ideal gas constant?

0.08206 L x atm/mol x K