1. Copyright 2012 CFT GAS/1 ISO 24801-2 / EN 14153-2 "AUTONOMOUS DIVER" Gas Laws

2. Copyright 2012 CFT GAS/2 We will cover Boyle's Law Dalton's Law Henry's Law Charles' Law

3. 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

4. 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

5. 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)

6. 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)

7. Copyright 2012 CFT GAS/7 Henry's Law High pressure Excess gas dissolved in liquid Cap sealed

8. 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

9. 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"

10. 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)

11. 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 (273 + 70) (273 + 20) = 271 Bar New pressure in cylinder = 271 Bar

12. 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

13. Copyright 2012 CFT GAS/13 ISO 24801-2 / EN 14153-2 "AUTONOMOUS DIVER" Questions

14. Copyright 2012 CFT GAS/14 Pressure and volume are inter-related by: a)Charles' Law? b)Boyle's Law? c)Henry's Law?

15. Copyright 2012 CFT GAS/15 Pressure and volume are inter-related by: a)Charles' Law? b)Boyle's Law? c)Henry's Law?

16. 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?

17. 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?

18. Copyright 2012 CFT GAS/18 The Gas Law used to explain the Bends is: a)Charles'? b)Dalton's? c)Henry's?

19. Copyright 2012 CFT GAS/19 The Gas Law used to explain the Bends is: a)Charles'? b)Dalton's? c)Henry's?

20. 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?

21. 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?

22. 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?

23. 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?

24. 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?

25. 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?

26. 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?

27. 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?