[raymanh]

Hi,
I desperately need to get the following answered: Any help is greatly received.

1. water contains the following concentration of ions in units ppm: Ca(2+)=3.8; Mg(2+)=0.31; Na(+)=0.86; K(+)=0.45; SO4(2-)=2.5; NO3(-)=0.28; Cl(-)=0.86

a) Estimate HCO3(-) concentration of the solution stating assumptions made.

b) The pH of the solution is 6.9. Calculate partial pressure of CO2 with which the solution is in apparent equilibrium.

c) If partial pressure in the atmosphere is 10-3.5 atm, what will happen to the pH of the above solution if left in contact with atmosphere

d) What is the saturation index with respect to calcite and aragonite? state the source of the products you use

2. Estimate solubility product of gibbsite, Al(OH)3, from change in gibbs free energy of the following reaction: Al(OH)3(s) <-> Al(3+)(aq) + 3OH(-)(aq) state source of free energy data. show units for values in calculations
Thanks