GASES

Question 1

How is the exertion of pressure created in gas?

Answer 1

frequent collisions between gas molecules, all the pressure in a gas is formed by collisions

Question 2

Describe the physical properties of gas

Answer 2

1. Diffusion: gas particles diffuse rapidly because of constant motion
2. Effusion: gas particles are capable of effusion - the leakage of gas through a small aperture
3. Compressibility
4. Pressure: frequent collisions with walls of container = exertion of pressure

Question 3

What is the unit for pressure and how is it measured?

Answer 3

The unit for pressure is the pascal (Pa)

It is measured by barometer, pressure gauge, or manometer

Question 4

What is an ideal gas?

Answer 4

There is no such thing as an ideal gas

We use the term to assume the respective gas is:

• Made of molecules in constant random motion
• Molecules moving in a straight line
• Molecules behave as a rigid shape
• No loss of kinetic energy through collisions
• temp of gas is proportional to the average kinetic energy of the molecules
• The volume occupied by molecules themselves is negligible relative to the volume of the container

Question 5

What is Boyle’s law?

Answer 5

For a fixed mass of an ideal gas at a constant temp, the volume of the gas is inversely proportional to the applied pressure

P1 x V1 = P2 x V2

Question 6

What is Charle’s law?

Answer 6

The volume of a fixed mass of an ideal gas at a constant pressure is directly proportional to the temp in Kelvin (K)

V1/T1 = V2/T2

Question 7

What is Gay-Lussac’s law?

Answer 7

At a constant mass and volume, the pressure of a gas is directly proportional to the temp

P1/T1 = P2/T2

Question 8

What is the combined gas law?

Answer 8

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

Question 9

What is molar volume?

Answer 9

The volume occupied by one mole of substance

Question 10

What is Avogadro’s hypothesis?

Answer 10

One mole of any gas should occupy the same volume under the same temperature and pressure

Question 11

What is the ideal gas law?

Answer 11

Combination of Avogadro's hypothesis and the combined gas law
P = Pressure (must be in atm)
V = Volume (must be in L)
T = Temp (must be in K)
n = moles 
R = ideal gas constant (0.0821 L atm mol^-1 K^-1)
PV/nT = R
PV = nRT

Question 12

What is Henry’s law?

Answer 12

Solubility of a gas in a solvent increases as the pressure of the gas over the solvent increases

Only applicable in molecules are at equilibrium

Does not apply for gases at high pressures4ewrtf

Question 13

What is Dalton’s law of partial pressure?

Answer 13

Total pressure of a mixture of gases is the sum of the partial pressure of each of its components