1. What is the concentration of NO gas at equilibrium if you mix 0.20 mol of N2 and 0.15 mol of O2 in a 1.0 L container at 2000 °C? The Kc for the reaction at 2000 °Cis 4.10×〖10〗^(-4).
2. What would be the equilibrium pH if 200 milligrams of Hydrofluoric acid (HF) were dissolved in 1 liter of solution? The pKa for the acid is equal to 3.2. (Hint: Convert pKa to Ka)
3. The Henry’s law constant for H2S is 0.1 mole/L.atm and
H2S <--->HS- + H+
Where Ka = 10-7. The equilibrium pH of the solution is 4.5 if pure H2S gas is dissolved in water. Find the partial pressure of the H2S gas above the solution.
4. At a wastewater treatment plant, FeCl3(s) is added to remove excess phosphate (PO4-3) from the effluent. Assume the following reactions occur:
FeCl3(s)<---> Fe3+ + 3Cl-
FePO4(s)<---> Fe3+ + PO4-3
The Ksp for the second reaction is 1.3×〖10〗^(-22). What concentration of Fe3+ (in mg/L) is needed to maintain the phosphate concentration below the limit of 1 mg/L P?