CHEM 1B   Dr. R. Rinehart
QUALITATIVE ANALYSIS
new, improved
 GROUP I FLOW CHART
and other goodies

grp1
 

 

 

STEP
 #

What is the PURPOSE
of this step?

What KEY EVENT(s)
will you be looking for?

All RELEVANT net ionic
equations for this step

1

dilute knowns to 0.1M

n/a

n/a

C1V1 = C2V2

2

precipitate Ag+ and/or Pb2+ as chlorides

white precipitates

HCl(aq) à H+(aq) + Cl-(aq)

Ag+(aq) + Cl-(aq)  à  AgCl(s)

Pb2+(aq) + 2Cl-(aq)   à   PbCl2(s)

3

insure complete precipitation

same as step 2

same as step 2

4

separate PbCl2
from AgCl

ppt dissolving or remaining

PbCl2(s) + H2O(l) + heat à Pb2+(aq) + 2Cl-(aq)

5

identify/confirm Ag+

ppt dissolves in NH3,

 reappears after HNO3 added

AgCl(s) + 2NH3(aq)  à  Ag(NH3)2+(aq) + Cl-(aq)

Ag(NH3)2+(aq) + Cl-(aq) + 2H+(aq)  à   AgCl(s) + 2NH4+(aq)

6

identify/confirm Pb2+

white ppt with (NH4)2CO3

Pb2+(aq)  +  CO3-2(aq)  à   PbCO3(s)

 
 
The reactions you should have written (along with the most useful info):


 
© Ronald W. Rinehart, 2002-9   Flow chart constructed using MS EXCEL™ [my favorite program]
The detailed protocol on which this flowchart is based was developed by Mark A. Bishop of MPC.

© Ronald W. Rinehart, 2002-9