Random - 3-7-2010 at 14:02
I tried mixing Ca(OH)2 with citric acid and the gas was made. Does this mean that my Ca(OH)2 has CaCO3 impurity?
After that I added some Ca(OH)2 to NaHCO3 water solution, aluminium didn't dissolve in that so no NaOH was made, but why?
Thanks for the answers.
JohnWW - 3-7-2010 at 14:08
Yes, your Ca(OH)2 - slaked lime - probably does contain some CaCO3, if at some stage it was left exposed to air from which it readily absorbs CO2,
which would be liberated on reaction with any acid stronger than H2CO3.
Aluminium probably did not dissolve to form aluminate in the NaHCO3 solution to which some Ca(OH)2 (a strong alkali) had been added, simply because
you had not added enough Ca(OH)2 to significantly more than neutralize the NaHCO3.
Reference - 14-7-2010 at 13:28
I have tried the reaction between CaO and Na2CO3 in water, and it WAS able to make some bubbles with aluminum foil, but only a little bit, and it took
a few minutes. I think using Na2CO3, which is more basic, more easily makes NaOH than using NaCO3H.
Soda Ash (Sodium carbonate) is available in little buckets at a pool supply very cheaply. Lime (calcium oxide) is sold next to the cement in a
warehouse home improvement store.
CaO and soda ash also react together in 70% isopropyl rubbing alcohal. I think I might be making
sodium isopropoxide (sort of like sodium methoxide).