CHM 2046C       Module 10 Sample Exam

Part G: LaChatelier’s Principle 10 points

Consider the isomerism of butane with an equilibrium constant of Kc = 2.5.

 CH3

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CH3-CH2-CH2-CH3 (n-butane)     ç è       CH3-CH-CH3 (isobutane)

 

The system is originally at equilibrium with [n-butane]=1.0 M and [isobutane]=2.5M.

(a) If 0.50 moles/liter of isobutane is suddenly added and the system shifts to a new equilibrium position, what is the equilibrium concentration of each gas?

 

 

 

 

 

 

 

 

 

 

(b) If 0.50 moles/liter of n-butane is suddenly added and the system shifts to a new equilibrium position, what is the equilibrium concentration of each gas?

 

                                                                             

 

 

 

 

 

 

 

The McMurry text does not do Calculations demonstrating LaChatelier’s Principle in Chapter 13 or 14, unlike most college chemistry texts. The first demonstration of LaChatelier’s Principle is in Chapter 15 with the Common Ion Effect problems. So you will have to study the worked examples in the grading outline.

 

However, in Kotz 6th Reference section 16.6 p 781-786 See Example 16.8 p784 for the effect of the addition or removal of a reactant or product. Try Exercise 16.11 p785 for the effect of adding or removing of a reactant or product and Exercise 16.12 p786 for the effect of concentration and Volume changes on the Equilibria.  Then go to the end of the chapter on page 791 and try #25-#28. The Solutions manual for these exercises have been distributed