1. CHEMISTRY 161 Chapter 5 www.chem.hawaii.edu/Bil301/welcome.html

2. REVISION Boyle’s Law Gay-Lussac’s Law Avogadro’s Law p ∞ 1/V n ∞ V V ∞ T

3. (1) p ∞ 1/V p × V = const × n × T (2) V ∞ T 1. IDEAL GAS EQUATION (3) n ∞ V V ∞ 1/p V ∞ T V ∞ n V ∞ T × n / p

4. p × V = const × n × T p × V = R × n × T p × V = n × R × T ieal gas equation

5. p × V = n × R × T [R] = [p] × [V] / [n] / [T] Pa = N/m 2 m3m3 molK [R] = N × m / mol / K [R] = J / mol / K

6. R = 8.314 J / mol / K [R] = J / mol / K ideal gas constant

7. p × V = n × R × T 2. MOLAR VOLUME What is the volume of 1 mol of a gas at 273.15 K (0 o C) and 1 atm (101,325 Pa)? standard temperature and pressure (STP) V = 22.4 l

8. p × V = n × R × T the molar volume at standard pressure and temperature is independent on the gas type V = 22.4 l V m = 22.4 l

9. 3. STOICHIOMETRY NaN 3 (s) → Na(s) + N 2 (g) How many liters of nitrogen gas are produced in the decomposition of 60.0 g sodium azide at 80 o C and 823 torr? 1.Balancing 2.Mole ratios 3.Convert grams into moles 4.Convert moles into liters

11. 4. DENSITY CALCULATION p × V = n × R × T ς = m / V relate the moles (n) to the mass (m) via the molecular weight (M) n = m / M m = n × M V = n × R × T / p ς = p × M / (R × T)

12. 5. DALTON’S LAW Dalton (1801) pure gases gas mixtures (atmospheres)

13. DALTON’S LAW the total pressure of a gas mixture, p, is the sum of the pressures of the individual gases (partial pressures) at a constant temperature and volume p = p A + p B + p C + ….

14. p A × V = n A × R × Tp A = n A × R × T / V p B × V = n B × R × T p × V = n × R × T p B = n B × R × T / V p = p A + p B p = (n A + n B ) × R × T / V p × V = n × R × T

15. p A = n A × R × T / V p × V = (n A + n B ) × R × T p A / p = n A /(n A + n B ) = x A mole fraction x < 1 p A = x A × p

16. A gas mixture contains 4.46 moles of neon, 0.74 moles of Ar, and 2.15 moles of xenon. Calculate the partial pressure of each gas if the total pressure is 2.0 atm.

17. 2 KClO 3 → 2 KCl + 3 O 2

18. SUMMARY p × V = n × R × T 1. ideal gas equation R = 8.314 J / mol / K V m = 22.4 l 2. molar volume

19. ς = p × M / (R × T) 3. Density of gases 4. Dalton’s Law p = Σ p i i=1 n

20. Homework Chapter 5, p. 166-179 problems