Copyright 2012 CFT GAS/1 ISO / EN "AUTONOMOUS DIVER" Gas 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 Boyles 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 (ppN 2 = 0.79 bar) Partial pressure of oxygen = 0.21 bar (ppO 2 = 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 High pressure Excess gas dissolved in liquid Cap sealed

Copyright 2012 CFT GAS/8 Henry's Law Cap removed Reduced pressure Reduced amount of gas can dissolve in liquid Gas Bubbling rushing 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) If P1P1 T1T1 = P2P2 T2T2 P 2 = P 1 x T 2 T1T1 P 2 = 232 x ( ) ( ) = 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/13 ISO / EN "AUTONOMOUS DIVER" Questions

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?