During the preparation of K3[Al(C2O4)3].3H2O, NaOH was added slowly and with stirring over an approximately 10-minute period to a solution of Al2(SO4)3 solution. The combined solution was heated to almost boiling and left to stand for a few minutes.
1. Why does NaOH added slowly with stirring over a 10-minute period?
2. Why was the combined solution heated and left to stand for a few minutes?
1 answer
You haven't written all of your procedure for the oxalate hasn't been added at this time. One reason NaOH is added slowly is to prevent the pptn of Al(OH)3.