chemical equilibrium!

1. chemical equilibrium!

2. First, a metaphor: Two floors of a store are connected by up and down escalators Floor 1 has 7 people, floor 2 has 12 people. There are always 2 people occupying each escalator

3. Floor 2: 7 people Floor 1: 12 people

4. Floor 2: 7 people 2 people on the up escalator Floor 1: 12 people 2 people on down escalator

5. Floor 2: 7 people 2 people on the up escalator Floor 1: 12 people 2 people on down escalator Question 1: if there are always two people on each escalator at any one moment, will the amount of people on each floor ever change?

6. Floor 2: 7 people 2 people on the up escalator Floor 1: 12 people 2 people on down escalator Question 2: if there are always two people on each escalator at any one moment, will the specific people occupying each floor ever change?

8. N2 + 3H2 2NH3 The double arrow tells us that this reaction can go in both directions:

9. N2 + 3H2 2NH3 1) Reactants react to become products, N2 + 3H2 2NH3 (‘forward’ reaction)

10. N2 + 3H2 2NH3 1) Reactants react to become products, N2 + 3H2 2NH3 (‘forward’ reaction) while simultaneously, 2) Products react to become reactants N2 + 3H2 2NH3 (‘reverse’ reaction)

11. N2 + 3H2 2NH3 In a closed system, where no reactants, products, or energy can be added to or removed from the reaction, a reversible reaction will reach equilibrium.

12. N2 + 3H2 2NH3 At equilibrium, the rateof the forward reaction becomes equal to the rate of the reverse reaction, and so, like our escalator metaphor, the two sides, reactants and products, will have constant amounts, even though the reactions continue to occur.

13. N2 + 3H2 2NH3 However (like the metaphor), the equilibrium amounts of reactants and products are usually not equal, they just remain unchanged.

14. N2 + 3H2 2NH3

15. N2 + 3H2 2NH3

16. N2 + 3H2 2NH3

17. N2 + 3H2 2NH3

23. reverse forward

24. reverse forward

25. reverse forward

26. reverse forward

27. reverse forward

30. reverse forward

31. reverse forward

32. reverse forward

33. reverse forward

34. reverse forward

36. reverse forward etc! the reactions go on continuously in both directions.

37. Changes in the concentrations of the reactants and products can be graphed; the graph indicates when equilibrium has been reached. concentration time

38. For N2 + 3H2 2NH3, suppose you begin with the following: N2 = 1 M, H2 = 1 M, and NH3 = 0 M concentration time

39. For N2 + 3H2 2NH3, suppose you begin with the following: N2 = 1 M, H2 = 1 M, andNH3 = 0 M concentration time

40. For N2 + 3H2 2NH3, suppose you begin with the following: N2 = 1 M, H2 = 1 M, andNH3 = 0 M concentration time

41. For N2 + 3H2 2NH3, suppose you begin with the following: N2 = 1 M, H2 = 1 M, andNH3 = 0 M concentration time

42. For N2 + 3H2 2NH3, suppose you begin with the following: N2 = 1 M, H2 = 1 M, andNH3 = 0 M concentration time

43. For N2 + 3H2 2NH3, suppose you begin with the following: N2 = 1 M, H2 = 1 M, andNH3 = 0 M concentration time

44. For N2 + 3H2 2NH3, suppose you begin with the following: N2 = 1 M, H2 = 1 M, andNH3 = 0 M concentration time

45. For N2 + 3H2 2NH3, suppose you begin with the following: N2 = 1 M, H2 = 1 M, andNH3 = 0 M concentration time

46. For N2 + 3H2 2NH3, suppose you begin with the following: N2 = 1 M, H2 = 1 M, andNH3 = 0 M concentration time

47. For N2 + 3H2 2NH3, suppose you begin with the following: N2 = 1 M, H2 = 1 M, andNH3 = 0 M concentration time

48. For N2 + 3H2 2NH3, suppose you begin with the following: N2 = 1 M, H2 = 1 M, andNH3 = 0 M concentration time

49. For N2 + 3H2 2NH3, suppose you begin with the following: N2 = 1 M, H2 = 1 M, andNH3 = 0 M concentration time

50. For N2 + 3H2 2NH3, suppose you begin with the following: N2 = 1 M, H2 = 1 M, andNH3 = 0 M concentration time