Precipitation

[edward]

I need to generate the following precipitation reaction:
(NH4)2CO3 + LiCl = Li2CO3 + NH4Cl

How can I add the compounds (NH 4)2CO3 and NH4Cl (Ammonium carbonate and ammonium chloride respectivment)
Thanks.

[dlparkhurst]

You can use Amm.dat, which has ammonium species split from the rest of the nitrogen system. Ammonia is defined as an "element", Amm. You can define a SOLUTION containing Amm, or you can add a REACTION containing Amm

REACTION
(AmmH)2CO3 1
0.1 mol

If you want to precipitate an ammonium phase, you probably need to define it with PHASES,

One caution. Amm.dat is an ion-association aqueous model, which means that it works best at relatively low ionic strengths. If you are working at very high ionic strengths, the model will probably not be accurate. A Pitzer model would be better, but ammonia is not included in the parameterizations of pitzer.dat. Adding the necessary parameters to include ammonium could be a large task.