A student had a set of solutions labeled A-E which contained in no order aquoeous soultions of KOH,H2SO4,Fe(NO3)2, HBr, and Mg(NO3)2. After the initial pH test they determined that A was a base,B/C were neutral and D/E were acids. They then mixed B and C with D and then E and got a precipitate with the BD and CE mixtures but not the BE or CD mixtures. They then came to the following erroneous conclusions A:KOH, B:FE(NO3)2 C:Mg(NO3)2 D: HBr and E: H2SO4 with the only correct identification being that solution A was KOH. What did they do wrong and what test should they have done to confirm their results? Solution What wrong they did war that they have not done the qualitative analysis of all the A, B, C, D and E to conclude what are the ions or species present. After that, qualitative analysis for the precipitate is also important. only looking at the acidic or basic behaviour of their solution, it is very difficult to confirm the species..

1. A student had a set of solutions labeled A-E which contained in no order aquoeous soultions of
KOH,H2SO4,Fe(NO3)2, HBr, and Mg(NO3)2. After the initial pH test they determined that A
was a base,B/C were neutral and D/E were acids. They then mixed B and C with D and then E
and got a precipitate with the BD and CE mixtures but not the BE or CD mixtures. They then
came to the following erroneous conclusions A:KOH, B:FE(NO3)2 C:Mg(NO3)2 D: HBr and E:
H2SO4 with the only correct identification being that solution A was KOH. What did they do
wrong and what test should they have done to confirm their results?
Solution
What wrong they did war that they have not done the qualitative analysis of all the A, B, C, D
and E to conclude what are the ions or species present. After that, qualitative analysis for the
precipitate is also important. only looking at the acidic or basic behaviour of their solution, it is
very difficult to confirm the species.