If a 0.10 M solution of silver fluoride, AgF, is mixed with a 0.10 M solution of barium acetate, Ba(C2H3O2)2, a pecipitate (ppt.) forms: AgF + Ba(C2H3O2)2--> ppt.

Question

In order to identify the precipitating ions, you conduct some experimental tests.
a) what is the purpose of this test (the solutions are 0.1 M):
AgF + NaC2H3O2--> ?
b) what do the test results below tell you about the AgF + Ba(C2H3O2)2 reactions?
AgF + Ba(NO3)2 --> precipitate (properties are identical to those of the ppt. formed in the AgF + Ba(C2H3O2)2 reaction)
c) which 0.10 M test reagant combination below did you use to directly test the hypothesis that silver ions are critical to precipitate formation?
AgF + Ba(NO3)2 NaF + Ba(C2H3O2)2 AgF + KC2H3O2

Answer 1

You conclude that the ppt is either BaF2 or AgC2H3O2.
a)You know NaF is soluble. A ppt here will tell you if AgC2H3O2 ppts.
b)Since you know AgNO3 is soluble, if a ppt forms it must be BaF2. Since that is identical to the ppt formed initially, I would conclude that the original ppt was BaF2.
c) I don't know what reagent you picked but NaF/Ba(NO3)2 combo looks good to me. You know Ba(NO3)2 is soluble, you know NaF is soluble, a ppt MUST be due to BaF2.