1) Calculate the solubility go Mg(OH)2 (i.e., the [Mg^2+]) in 0.0167M Na2SO4 solution solution taking into account activity. The ion size's for Mg^2+ and OH^- are 800pm and 350pm, respectively. The Ksp for Mg(OH)2 is 2x10^-13.
2) a) Calculate the pH of a solution that is 0.04M in NH3, and 0.05M in NH4Cl. b) What is the resulting pH of solution made by adding 5.0mL of 0.10M NaOH to 100mL of the solution in part (a)?(the Ka for NH4^+ is 5.70x10^-10)
3) a) Calculate the pH of a solution prepared by adding 2.5202g of NaHC2O4 in 500.0mL of distilled water? (MW NaHC2O4=112.009 g/mole). Write down the appropriate alpha-equation for [H2C2O4] at this pH? (for oxalic acid Ka1=0.0560, and Ka2=5.42x10^-5).