# Solubility Equilibria and Calculations

Name: _________________________

1)  Given the following reactions and equilibrium constants:

$\ce{SnO2 (s) + 2 H2 (g) ⇆ Sn (s) + 2 H2O (g)} \hspace{30px} \mathrm{K_1 = 8.12}\nonumber$

$\ce{H2 (g) + CO2 (g) ⇆ H2O (g) + CO (g)} \hspace{30px} \mathrm{K_2 = 0.771}\nonumber$

Calculate K3 for the reaction:

$\ce{SnO2 (s) + 2 CO (g) ↔ Sn (s) + 2 CO2 (g)}\nonumber$

2) Consider a solution that is to be made 0.01 M in each of the following ions: Ba2+ and  CrO42-. We assume these are concentrations present initially, before any reaction has occurred. Calculate the reaction quotient (Q) to determine whether or not BaCrO4 will precipitate out of the solution.

$\ce{BaCrO4(s) ↔ Ba^2+ + CrO4^2-}\nonumber$

If Q = Ksp, solution is saturated; if Q < Ksp, undersaturated; if Q > Ksp, supersaturated.

3) Calculate the solubility (in deionized water) of the following compound.  Express the solubility of CuN3, copper(I) azide in mol/L.

$\ce{CuN3 (s) ↔ Cu+(aq) + N3- (aq)} \hspace{30px} \mathrm{K_{sp} = 4.9 \times 10^{-9}}\nonumber$

Name: _________________________

1) Use the systematic treatment of equilibrium to determine [Zn2+] in a saturated solution of Zn(CN)2 with a fixed pH of 3.110.  The Ka for HCN is 6.2x10-10

Name: _________________________

1) Find the relative error introduced by neglecting activity in calculating the solubility of Ba(IO3)2 in a 500 mL solution that is 0.033M CaCl2.  The Ksp of Ba(IO3)2 = 1.57x10-9