Retard-3000 - 17-11-2010 at 12:30
i am trying to synthesis calcium chloride using equal stoichiometric quantities of HCl and Ca(OH)2, when i reacted the 2 together i noticed a gas
bubbling out which i'm guessing is CO2 due to calcium carbonate impurities, however during the reaction the solution turns a bright yellow colour,
does anyone know why this is ?
not_important - 17-11-2010 at 12:56
Using hardware store muratic acid? Usually has traces of iron, which colours the acid green-yellow and in higher but still acid pH gives a yellow
colour.
Retard-3000 - 17-11-2010 at 13:22
i'm using around 32% hydrochloric acid which i bought off ebay from a seller that seems to be part of a chemical company, i guess i'll just leave it
to the highly acidic pH, thanks.
Random - 17-11-2010 at 15:25
maybe ca(oh)2 has some impurity, I remember that I used builder's lime and when I mixed it with almost white vinegar I got yellow solution.
unionised - 18-11-2010 at 11:22
If you add an excess of Ca(OH)2 you should convert iron to the hydrated oxide which you can filter off (together with the excess lime).
That should get rid of most of the yellow colour and give a purer product.