Solubility Rules applied to various reactions

Use the Solubility Rules to write net ionic equations for the reactions that occur when solutions of the following are mixed. a) K2S + ZnSO4 b) K2CrO4 + NiCl2 c) CsOH + FeCl3 [2] d) CuSO4 + Pb(ClO4)2 e) FeSO4 + K3PO4 f) FeCl2 + TlNO3 g) (NH4)2CO3 + Ni(ClO4)2

pH of Co2 saturated water

Please show how to solve. Calculate the pH of CO2-saturated water at 25 degrees C, given that the CO2 concentration in air is 338 and that for carbon dioxide the Henry's Law constant KH=3.4E-2 mol L-1 atm-1 at 25 degrees C. Furthermore, the ionization constant, Ka, for H2CO3 has a value of 4.5E-7 mol L-1 at this temperature.

Acid Mine Water

I have looked at a solution and was not able to come up with a correct answer. Please show how to solve this problem: What is the calculated value of the partial pressure(atm) of O2 in acid mine water of pH 2.700, in which [Fe3+] = [Fe2+]? Hint: Application of the Nernst Equation

Groundwater

I have already looked at a few solutions and none have worked to come up with a correct solution. Please show how to solve this problem. A ground water sample , at 25 C, has Eh= 1.0 and pH=6.80. Assuming the system is at equilibrium, calculate the amount of dissolved oxygen (ppm) in the groundwater sample.

Gasoline

I thought I had the answer but I was wrong. Please show how to solve. Calculate the mass percent of methanol, ethanol, and MTBE each that must be present in gasoline to yield a mixture of 2.9 % oxygen by weight. Hint given: Calculate percent oxygen in each compound. I don't have the density of the gasoline in the question or in the textbook. However, all I can find relevant in the textbook is that the octane number of Methanol is 116, ethanol is 112, and MTBE is 116 and that gasoline produced simply by distillation of crude oil has an octane number of about 50.