Hey everyone, just created the account to ask something..
Why do we need to add NH3 to CaCl2 on the way to make Ca3(PO4)2?
1st year on University of Chemistry in Greece here and I gotta write a report on an experiment we did the other day.. Based on the directions from a book they had given us, we needed to make Ca3(PO4)2. The steps were these:
1.Get 2,50 g of pure, dry CaCl2 in a 100ml beaker.
2.Add 25ml H2O so they dissolve.
3.Add SOME dense NH3.(Sorry if the word dense isn't correct I'm from, and study in, Greece.. Anyway I mean high concentration.)
4.Filter if neccesary.
5.In a different beaker dissolve 5,00 g Na2HPO4*12H2O in H2O.
6.Heat both solutions and then combine them while stirring.
7.Keep the solution warm for a while so that the sediment becomes granular and drops.
8.Filter using the Buchner filtration system.
9.Wash with warm H2O (twice with 5ml each time).
10.Dry in a drying oven.
So on step 3 why do we need to add the NH3?? It doesn't say and the teacher wouldn't explain.. We need to calculate how much we need to add but we do not know why add it in the 1st place.. So please If anyone can help me I'd be quite grateful..