Base Calculations

[Vibrating_Lights]

What rules do i use to determine How much sodium carbonate to add to a mix of MeCN:H2O2:MeOH:Alkene to make the Ph 8 for an epoxidation?
VL_

[Rhodium]

pH paper is the best method.

[Vibrating_Lights]

Surely there is a way to calculate it before hand.  Whata gives.  I can't even think of where to look for such info.
Vl_

[Megatherium]

pH calculations are only valid in an aqueous medium (i.e. not in a acetonitrile / methanol mix).

[Rhodium]

Megatherium: That is not exactly true, you can make valid pH calculations in all protic solvents (such as methanol), not exclusively in water. However, you need to use a completely different set of variables than when doing it for aqueous solutions.

V_L: It's nice that you are trying to learn, but it is incredibly difficult to calculate beforehand what pH an aqueous mixture will have if you are adding several different solutes, as well as aubstances which aren't simple acids and bases. In this case, when it isn't even an aqueous solution, then you are really far out...