1. U1 S3 L2 Equilibrium Calculations – p 505 – 510 The meaning of a small equilibrium constant – p 513 - 514 Homework: P 508 # 11,12,13, and15 (no ice for 11 and 12) P 511 #16-19 P 515 #25-29 P 535-537 items: 8, 13, 14, 15, 16 p 538-540: items 6,18, 24, 25 and 26 Let me show you how its done……

2. These calculations may drive you crazy!

3. Upon completion of this lesson, you will be able to: calculate equilibrium concentrations for simple chemical systems when : –initial concentrations of reactants and one equilibrium concentration are known –initial concentrations of reactants and percent reaction are known calculate equilibrium constants, K, for simple chemical systems when: –initial concentrations and one equilibrium concentration are known –initial concentrations and the percent reaction of one of the reactants are known

4. ICE Tables An ICE table is a way of organizing given and calculated data. The three letters in the acronym stand for Initial, Change, and Equilibrium.

5. Sample 1: An equilibrium was established after 0.100 mol of hydrogen gas and 0.100 mol of iodine gas were added to an empty 1.00 L reaction vessel and heated to 700 K. The colour intensity of the mixture changed from deep purple to a lighter purple colour. At equilibrium, concentration of iodine was 0.0213 mol/L. Calculate the equilibrium concentrations of hydrogen gas and hydrogen iodide gas. Initial Change Equilibrium

6. Sample #2: Percent reaction In a 1.00 L vessel, 0.200 mol of nitrogen gas and 0.200 mol of oxygen gas were reacted at 773 K to produce nitrogen monoxide gas. The percent reaction was found to be 12.5%. Calculate the equilibrium concentrations of all three species. Initial Change Equilibrium

7. Sample #3: An equilibrium was established in a 1.00 L container when 0.120 mol of phosphorus pentachloride gas was decomposed at 500 K. At equilibrium, the concentration of chlorine gas was 0.0540 mol/L. Calculate the equilibrium constant for this system and state a conclusion about the position of the equilibrium Initial Change Equilibrium

8. Sample #4: The second step in the water gas reaction involves reacting carbon monoxide with water vapour to make hydrogen gas. When 0.570 mol of carbon monoxide gas and 0.570 mol of water vapour are introduced into a 1.00 L container at 600 K, they react to form carbon dioxide gas and hydrogen gas. The percent reaction of carbon monoxide is found to be 82.8%. Calculate the equilibrium constant for this system at 600 K and state a conclusion about the position of the equilibrium. Initial Change Equilibrium

9. #19 p 511

10. #15 p 509 - no equilibrium values given??? What to do!

11. Da rule! – da 500 times rule! Rule for simplifying ice tables when the K value is very tiny If > 500 then x is negligible If < 500 the x is significant and we must solve using the quadratic equation.

12. #25 p 515

13. #27 p 515