Spring 2009 CH302 Worksheet 4:
Chemical Equilibria and an Introduction to Water Chemistry
Please note that all calculations below can be worked without the aid of a calculator.
1. Write a mass action quotient for the following chemical equation:
CaCO3(s) Ù CaO(s) + CO2(g)
2. Write a mass action quotient for the following chemical equation:
H2O(l) H+(aq) + OH-(aq)
3. Based on your answers to numbers 1 & 2, what types of reactants and products always appear in mass
action quotients? What types never appear in mass action quotients? Why?
4. What are the units of all equilibrium constants?
5. Complete the RICE diagram below. Express unknown quantities in terms of X.
Reaction CO(g) + NO2(g) Ù CO2(g) + NO(g)
Initial 5 M 5 M 0 M
Change
Equilibrium 8 M
6. Assuming K = 0.5, what was the initial concentration of NO(g)?
7. How would the chemical system in numbers 5 & 6 respond to a decrease in volume? What about
addition of CO(g)? What about removal of NO(g)?
8. The Clausius-Clapeyron equation and the van't Hoff equation are very similar in appearance. What is
the main difference between the two equations and why are they so similar?
9. Based on the van't Hoff equation, how will an exothermic reactions equilibrium constant respond to
changes in temperature? What about an endothermic reaction?
10. In a 1 liter container you initially have one mole of each species below.
4Fe(s) + 3O2(g) 2Fe2O3(s) K = 1012
What happens as this system approaches equilibrium?
