Gases

Question 1

The Properties of Gasses:

Answer 1

Gasses always fill their containers, they are highly compressible, they diffuse, they expand when heated, and confined gasses experience increased pressure when heated.

Question 2

What are the Kinetic Molecular Theory assumptions for ideal gasses?

Answer 2

1. Gas molecules are very far apart from one another 2. Gas molecules are in constant random straight-line motion because no forces exist between them 3. Gas molecules undergo perfect elastic collisions where no energy is lost.

Question 3

Temperature:

Answer 3

The average kinetic energy of a particle in a substance.

Question 4

Large motion = high kinetic energy = ____ temperature

Answer 4

high

Question 5

Absolute zero:

Answer 5

The temperature at which the motion of particles stops.

Question 6

Kelvin scale is based on what?

Answer 6

Absolute zero.

Question 7

Zero kelvin = _______ degrees Celcius.

Answer 7

-273.15

Question 8

What is the unit used for pressure?

Answer 8

kPa

Question 9

The greater the pressure, the _______ the volume.

Answer 9

smaller

Question 10

What two things need to be constant for Boyle’s Law to hold true?

Answer 10

Temperature and number of mols.

Question 11

What did Boyle’s Law state?

Answer 11

Volume is inversely proportional to the pressure at a constant temperature.

Question 12

What did Charles’ Law state?

Answer 12

Volume is directly proportional to its Kelvin temperature if pressure is constant.

Question 13

What two things need to be constant for Charles’ Law to hold true?

Answer 13

Pressure and number of mols.

Question 14

Skeleton equation:

Answer 14

An unbalanced formula equation.

Question 15

The law of Conservation of Mass states that the mass of the _______ = the mass of the ________.

Answer 15

product, reactant

Question 16

Gay-Lussac’s law:

Answer 16

The volume of gasses in a chemical reaction is always in whole-number ratios.

Question 17

Avogadro’s Theory:

Answer 17

The Law of combining Volumes: Equal volumes of gasses at the same pressure and temperature contain an equal number of molecules. The volume of gas is directly proportional to the number of mols present.

Question 18

If gas increases in temperature, what will happen?

Answer 18

The volume will increase in an elastic container, the pressure will increase in a rigid container.

Question 19

If a gas decreases in volume what will happen?

Answer 19

The pressure and temperature will increase in a rigid container.

Question 20

If a gas increases in pressure what will happen?

Answer 20

The volume will increase in an elastic container, the temperature will increase in a rigid container.

Question 21

Ideal Gas Law:

Answer 21

Used to relate temperature, pressure, volume, and mols together. The ideal gas constant is used to do this; 8.314.

Question 22

What are situations where gas will not behave like gas?

Answer 22

Under high-pressure molecules are forced close to each other and their size becomes significant. Under cold temperatures, the molecules slow down and will eventually condense and become liquid ie. water droplets on a mirror from a steamy shower. When molecules collide they lose energy meaning that pressure is less than ideal. When molecules condense ie. steam, they begin to have intermolecular forces ie. dipole-dipole and the random collisions are no longer random.

Question 23

Vapour pressure calculations:

Answer 23

Laboratory vapour pressure - water vapour pressure