
Spring 2008 

Exercise: Chemical Equilibrium 


Discussion Modules 


1. Consider the reaction
Note that heat appears on the product side  the system is giving up heat, therefore H is negative, H =  92.2 kJ
Using Le Châtelier's Principle, predict what will happen to [NH_{3}] if:
 N_{2} is added?
 H_{2} is removed?
 T is decreased?
 Ar is added?
Predict how the equilibrium will shift (right, left, or neither) if:
 V is increased?
2. Consider the gas phase reaction:
2 HI H_{2} + I _{2} K_{eq} = 2.06 x 10^{2} @ 458°C
If both hydrogen and iodine are measured to have concentrations of 0.0135 M each at 458°C, what is the concentration hydrogen iodide?
3. Consider the gas phase reaction:
2 HBr H_{2} + Br_{2}
K_{eq} = 1.5 x 10^{5} @ 1400 K Calculate the concentrations of all species at equilibrium if we start with 0.15 moles each of hydrogen bromide and bromine in a 0.500 L container at 1400 K.
4. Consider the gas phase dissociation of carbon dioxide to carbon monoxide and oxygen @ 1000 K.
If 0.200 moles of carbon dioxide is placed in a 1.00 L container at 1000 K calculate the concentrations of all species at equilibrium. K_{eq} = 4.5 x 10^{23} @ 1000 K.
Answers 14
In addition to these exercises you should familiarize yourself with text materials.
© R A Paselk
Last modified 4 December 2008