copyright 2012 cft gas/1 iso 24801-2 / en 14153-2 "autonomous diver" gas laws
TRANSCRIPT
Copyright 2012 CFT GAS/1ISO 24801-2 / EN 14153-2 "AUTONOMOUS DIVER"
Gas LawsGas Laws
Copyright 2012 CFT GAS/2
We will cover Boyle's Law Dalton's Law Henry's Law Charles' Law
Copyright 2012 CFT GAS/3
Boyle’s Law
“At a constant temperature, the volume of a given mass of gas varies inversely with the absolute
pressure”
Copyright 2012 CFT GAS/4
Dalton's Law
“In a mixture of gases, each constituent gas exerts a Partial Pressure in proportion to its percentage
of the mixture”
Copyright 2012 CFT GAS/5
Dalton's Law(Example)
Pure air at 1 bar pressure Air consists 79% nitrogen and 21% oxygen Partial pressure of nitrogen
= 0.79 bar (ppN2 = 0.79 bar) Partial pressure of oxygen
= 0.21 bar (ppO2 = 0.21 bar)
Copyright 2012 CFT GAS/6
Henry's Law
"The amount of gas that dissolves in a liquid is proportional to the partial pressure of the gas in
contact with the liquid"(Providing temperature is constant)
Copyright 2012 CFT GAS/7
Henry's Law
Highpressure
Excessgas
dissolvedin liquid
Cap sealed
Copyright 2012 CFT GAS/8
Henry's Law
Cap removed
Reducedpressure
Reduced amountof gas
can dissolvein liquid
Gas Bubblingrushing out
of liquid
Copyright 2012 CFT GAS/9
Charles' Law
"At constant pressure the volume of a gas varies directly with the absolute temperature"
or"At constant volume the pressure of a gas varies
directly with the absolute temperature"
Copyright 2012 CFT GAS/10
Charles' Law(Example)
Cylinder pressure = 232 Bar (P1) Original temperature = (20°C) 293 K (T1) Temperature increase to (70°C) 343 K (T2)
Copyright 2012 CFT GAS/11
Charles' Law(Example)
IfP1
T1
=P2
T2
P2 = P1 x T2
T1
P2 = 232 x (273 + 70)
(273 + 20)
= 271 Bar
New pressure in cylinder = 271 Bar
Copyright 2012 CFT GAS/12
Gas Laws Summary Boyle's Law
Relates pressure and volume Dalton's Law
Defines partial pressure exerted by individual gases in a mixture of gases
Henry's Law Defines the solubility of gases in a liquid
Charles' Law Relates change in pressure and volume of gases to
changes in temperature
Copyright 2012 CFT GAS/13ISO 24801-2 / EN 14153-2 "AUTONOMOUS DIVER"
QuestionsQuestions
Copyright 2012 CFT GAS/14
Pressure and volume are inter-related by:
a) Charles' Law?b) Boyle's Law?c) Henry's Law?
Copyright 2012 CFT GAS/15
Pressure and volume are inter-related by:
a) Charles' Law?b) Boyle's Law?c) Henry's Law?
Copyright 2012 CFT GAS/16
Dalton's Law deals with:
a) Pressure changes due to temperature increases?
b) Volume changes due to temperature increases?c) Partial pressures of gases?
Copyright 2012 CFT GAS/17
Dalton's Law deals with:
a) Pressure changes due to temperature increases?
b) Volume changes due to temperature increases?c) Partial pressures of gases?
Copyright 2012 CFT GAS/18
The Gas Law used to explain the Bends is:
a) Charles'? b) Dalton's?c) Henry's?
Copyright 2012 CFT GAS/19
The Gas Law used to explain the Bends is:
a) Charles'? b) Dalton's?c) Henry's?
Copyright 2012 CFT GAS/20
At a depth of 20 metres in sea water the partial pressure of
nitrogen in the air supply will be _____ times the partial pressure
which it is at the surface:a) Two?b) Three?c) Four?
Copyright 2012 CFT GAS/21
At a depth of 20 metres in sea water the partial pressure of
nitrogen in the air supply will be _____ times the partial pressure
which it is at the surface:a) Two?b) Three?c) Four?
Copyright 2012 CFT GAS/22
Exposing a full diving cylinder to excessive heat is not
recommended because:a) The paint may deteriorate and allow rust?b) The rubber seals involved may perish and give
rise to air leaks?c) The internal air pressure may rise excessively?
Copyright 2012 CFT GAS/23
Exposing a full diving cylinder to excessive heat is not
recommended because:a) The paint may deteriorate and allow rust?b) The rubber seals involved may perish and give
rise to air leaks?c) The internal air pressure may rise
excessively?
Copyright 2012 CFT GAS/24
Serious diving ailments such as Nitrogen Narcosis are explained
using:a) Boyle's Law?b) Charles' Law?c) Dalton's Law?
Copyright 2012 CFT GAS/25
Serious diving ailments such as Nitrogen Narcosis are explained
using:a) Boyle's Law?b) Charles' Law?c) Dalton's Law?
Copyright 2012 CFT GAS/26
The analogy of the bubbles forming in a fizzy drink when the
bottle is opened is used to explain:
a) The Bends?b) Oxygen Starvation?c) Nitrogen Narcosis?
Copyright 2012 CFT GAS/27
The analogy of the bubbles forming in a fizzy drink when the
bottle is opened is used to explain:
a) The Bends?b) Oxygen Starvation?c) Nitrogen Narcosis?