Peter, Paul, and Mary, members of a thermodynamics class, are asked to find the equilibrium composition at a particular T and P and for given initial amounts of reactants for the following gas-phase reaction:

2NH₃  + 3NO → 3 H₂O + N₂        (A)

Each solves the problem correctly in a different way. Mary bases her solution on reaction (A) as written. Paul, who prefers whole numbers, multiplies reaction (A) by 2:

4NH₃  + 6NO → 6H₂O + 5N₂        (B)

Peter, who usually does things backward, deals with the reaction:

3H₂O + N₂  → 2NH₃  + 3NO      (C)

Write the chemical-equilibrium equations for the three reactions, indicate how the equilibrium constants are related, and show why Peter, Paul, and Mary all obtain the same result.

Transcribed Image Text:

5 2. 7.