In deriving boyles law charles law we assume idealgas. what happens if we do not assume ideal gas situation?
Answers
mmmmmmaaaaaaaammmmmmmmmaaaaaaaaa
Answer:
An Ideal Gas is also known as a Perfect Gas.
An Ideal Gas is one which obeys Boyle's Law and Charles' Law exactly.
An Ideal Gas obeys the Ideal Gas Law (also known as the General gas equation):
PV = nRT
where
P = pressure
V = volume
n = moles of gas
T = temperature
R = gas constant (dependent on the units of pressure, temperature and volume)
R = 8.314 J K-1 mol-1 if (a) Pressure is in kilopascals (kPa)
(b) Volume is in litres (L)
(c) Temperature is in kelvin (K)
R = 0.0821 L atm K-1 mol-1 if (a) Pressure is in atmospheres (atm)
(b) Volume is in litres (L)
(c) Temperature is in kelvin (K)
An Ideal Gas is modelled on the Kinetic Theory of Gases which has 4 basic postulates:
Gases consist of small particles (molecules) which are in continuous random motion
The volume of the molecules present is negligible compared to the total volume occupied by the gas
Intermolecular forces are negligible
Pressure is due to the gas molecules colliding with the walls of the container
Real Gases deviate from Ideal Gas Behaviour because:
at low temperatures the gas molecules have less kinetic energy (move around less) so they do attract each other
at high pressures the gas molecules are forced closer together so that the volume of the gas molecules becomes significant compared to the volume the gas occupies
Under ordinary conditions, deviations from Ideal Gas behaviour are so slight that they can be neglected
A gas which deviates from Ideal Gas behaviour is called a non-ideal gas.
V = nRT
V
P = nRT
V
Calculate moles of hydrogen gas, n,
Hydrogen gas is a diatomic molecule with the molecular formula H2(g)
moles = mass ÷ molar mass
mass = 20.16 g (given in question)
molar mass of a hydrogen atom = 1.008 g mol-1 (from Periodic Table)
molar mass of hydrogen gas molecule = 2 × 1.008 = 2.016 g mol-1
n(H2(g)) = 20.16 ÷ 2.016 = 10.00 mol
Substitute in the values and solve for P:
P = n × R × T
V
= 10 × 8.314 × 293
7.5
= 3248 kPa
Is your answer plausible?
Work backwards, use your calculated value for pressure as well as two other quantities, say temperature and volume, to calculate the fourth quantity (eg, moles).
n = P × V
R × T
= 3248 × 7.5
8.314 × 293
= 10 mol
1 mole H2 has a mass of about 2 g mol-1
So 10 mole H2 has a mass of about 10 mol × 2 g mol-1 = 20 g
Since this "rough calculation" is in good agreement with the value given in the question, we are reasonably confident that our answer for gas pressure is plausible.
State your solution to the problem "pressure of gas":
P = 3248 kPa