posted by JES .
group 1 cations:
im doing a lab report for a experiment we did today. we had a known and we checked it for pb^+2, Hg2^+2, and Ag^+1.
we have to write our observations for:
A Precipitation of group 1.
what does this mean?
i understand the other questions, the others are about the separation and confirmation of the 3 cations i mentioned, but what is the precipitation of group 1. help! =(
do i just write overall the steps and what happened?
Yes, but I'm not sure what it is you don't understand. In general terms precipitate group I means how did you get all metals in group I to precipitate (form an insoluble material). The answer to that is that you added HCl (you add the concn and amount and the volume of unknown you used). The addition of HCl causes any metal in group I to ppt as the chloride; i.e., Ag^+ ppts as AgCl, Hg2^+2 ppts as Hg2Cl2, and Pb^+2 ppts as PbCl2. If, upon adding dilute HCl to the unknown you get a white ppt, it means one of those (or all of them) are present. Then you go through the separation steps to determine which are present and which are not present.
ok, thanks! i just wanted to be sure before i wrote down the answer.