Qualitative Cation Test Labpaq

Qualitative Cation Tests

Peter Jeschofnig, Ph.D. Version 42-0194-00-01

Lab Report Assistant

This document is not meant to be a substitute for a formal laboratory report. The Lab Report Assistant is simply a summary of the experiment’s questions, diagrams if needed, and data tables that should be addressed in a formal lab report. The intent is to facilitate students’ writing of lab reports by providing this information in an editable file which can be sent to an instructor.

Observations

Questions

A. Write net ionic equations for all reactions that produce a precipitate. Ag+(aq.) + Cl-(aq.) ---- AgCl (s)
2 Ag+(aq.)+ 2OH- --- Ag2O (s) + H2O(l)
2 Ag+(aq.)+2NH3+ H2O(l) --- Ag2O (s)+ 2NH4+ (aq.)
Pb2+(aq.)+2Cl- (aq.) ---- PbCl2(s)
Pb2+(aq.)+2OH-(aq.) ----Pb(OH)2 (s)
Pb2+(aq.)+ 2NH3(aq.)+ H2O(l) --- Pb(OH)2 (s)+ 2NH4+ (aq.)
Cu2+(aq.) +2OH-(aq.) ---- Cu(OH)2 (s)
2Cu2+(aq.)+SO42- (aq.) +2NH3(aq.)+2 H2O(l) ----- Cu(OH)2.CuSO4(s) +2NH4+ (aq.)
Zn2+ (aq.)+ 2OH- (aq.) ---- Zn(OH)2 (s)
Zn2+ (aq.)+2NH3(aq.)+ H2O(l) --- Ag2O (s)+ 2NH4+ (aq.)
Fe3+ (aq.)+ 3OH- (aq.) ---- Fe(OH)3(s)
Fe3+ (aq.)+ 3NH3(aq.)+ 3H2O(l) --- Fe(OH)3(s)+ 3NH4+ (aq.)
Pb2+(aq.)+ CrO42-(aq.) PbCrO4(s)
2Cu2+(aq.)+[Fe(CN)6]4- (aq.) -----Cu2[Fe(CN)6] (s) Zn2+(aq.) + S2-(aq) ----- ZnS(s)
4Fe3+ (aq.)+3[Fe(CN)6]4- (aq.) ----Fe4[Fe(CN)6]3 (s)
Ca2+(aq) + ( COO)22-(aq) ----- Ca(COO)2 (s)

B. Identify the cations that precipitate with hydrochloric acid and dissolve in the presence of ammonia. Ag+

C. Identify the cations that precipitate with hydrochloric acid and do not redissolve in the presence of ammonia. Pb2+

D. Identify the cations that precipitate upon addition of