Gases

Question 1

Definition of Energy

Answer 1

Capacity to do work

Question 2

Definition of Work

Answer 2

Motion against force

Question 3

Boyle’s Law

Answer 3

At a constant temperature the volume of a fixed amount fo a gas is reduced as pressure increases.

Pressure is therefore inversely proportional to Volume given Temperature and Moles are constant

Question 4

Charles’s Law

Answer 4

At a constant pressure, the volume of a fixed about of gas increases linearly with rising temperature.

Volume is therefore directly proportional to Temperature given Pressure and Moles are constant

Question 5

Avogadro’s Law

Answer 5

Equal volumes of gases at constant temperature and pressure contain equal number of molecules.

Volume is therefore directly proportional to Moles given Temperature and Pressure are constant

Question 6

Combination of Laws

Answer 6

This gives Volume is directly proportional to nT/p. Therefore pV is directly proportional to nT.

This proportionality is equal to multiplying by universal gas constant to give the Ideal Gas Equation.

Question 7

Assumptions of Ideal Gas

Answer 7

Particles have no volume.

Particles have no interactions with other particles.

Question 8

SI Units of Pressure

Answer 8

Pascals.

Question 9

Equation for Pressure

Answer 9

Pressure = HeightDensityAcceleration due to gravity

p = phg

Question 10

Standard Conditions and Molar Volumes

Answer 10

298.15 K and 1 bar (1x10^5 Pa)

Question 11

Partial Pressure Ideal Gas pointers

Answer 11

Mole Fraction = Partial Pressure/Total Volume

Question 12

Further Considerations of an Ideal Gas

Answer 12

No Rotational or Vibrational kinetic energy.
No intermolecular forces within an ideal gas.
No Electrostatic potential energy.
Internal energy of an ideal gas is determined by Temperature.
Thermodynamic state of an ideal gas determined by any two of: Pressure, Volume and Temperature.