1 / 6

Equilibrium Calculations Lesson 2

Equilibrium Calculations Lesson 2. How can we describe an equilibrium system mathematically? Keq = = 2.5 The Keq is the equilibrium constant - a number that does not change. Providing the temperature is kept constant. products. reactants. products. reactants.

louisa
Download Presentation

Equilibrium Calculations Lesson 2

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Equilibrium Calculations Lesson 2

  2. How can we describe an equilibrium system mathematically? Keq = = 2.5 The Keq is the equilibrium constant- a number that does not change. Providing the temperature is kept constant. products reactants products reactants

  3. Equilibrium Calculations An equilibrium system, at any given temperature, can be described by an equilibrium expression and equilibrium constant. aA + bB ⇌cC + dD Keq = Products Reactants Equilibrium ConstantExpression Keq = [C]c[D]d [A]a[B]b (aq) and (g) are included! (l) and (s) are not-constant concentration!

  4. 1. At equilibrium at 25oC, [SO3] = 0.200 M. [H2O] = 0.480 M, and [H2SO4] = 24 M. Calculate the Keq. Do not use ice! SO3(g) + H2O(g) ⇌ H2SO4(l) Keq = 1 [SO3] [H2O] don’t count (l)! Use 1 = 1 (0.200)(0.480) = 10.4 The Keq has no units but concentration units that go in the expression must be M!

  5. 2. 0.500 mole PCl5, 0.40 mole H2O, 0.200 mole HCl, and 0.400 mole POCl3 are found in a 2.0 L container at equilibrium at 125 oC. Calculate the Keq. PCl5(s) + H2O(g)⇄ 2HCl(g) + POCl3(g) Do not count the solid! [HCl] = 0.200 moles = 0.10 M 2.0 L [POCl] = 0.400 moles = 0.20 M 2.0 L [H2O] = 0.40 moles = 0.20 M 2.0 L Keq = [HCl]2[POCl3] [H2O] = (0.10)2(0.20)= 0.010 (0.20)

  6. 3. If 0.600 mole of SO3 and 0.0200 mole of SO2 are found in a 2.00 L container at equilibrium at 25 oC. Calculate the [O2]. 2SO2(g) + O2(g)⇄ 2SO3(g) Keq = 798 [SO3] = 0.600 mole/2.00 L = 0.300 M [SO2] = 0.0200 mole/2.00 L = 0.0100 M Keq = [SO 3]2 [SO2]2[O2] 798 = [0.300]2 1[0.0100]2[O2] (0.3)2 = 798(0.01)2[O2] [O2] = (0.3)2 = 1.13 M 798(0.01)2

More Related