group 1 cations Flashcards
Pb2+ and HCl gives?
PbCl2 white ppt
List the products formed when the group reagent of group 1 reacts with the cations?
The grp reagent is Hcl it froms PbCl2, Hg2Cl2 and AgCl all of which are white in colour ppts.
what will happen when the grp 1 cations react with hcl and nh3?
lead forms pbcl2 and Pb(oh)2 a white ppt | hg2 thingy forms hg(black) + hg(nh)2cl ( white ) | silver dissolves and forms [ag(nh3)2]+
i boil these cations with hcl, which one of them dissolves as the others do not change?
lead dissolves, rest do not change.
potassium iodide in a small amount reacts and gives what colours
pb ke saath we get pbI2 ( yellow), hg2 ke saath green and finally ag ke saath agI ( yellow)
which cation undregoes no change upon excess addition of KI?
ur mom silver.
lead also doesn’t undergo change but at one particular concentration of KI it does. what is that concentration amount?
The concentration of KI is 6M. IT ends up forming [PbI4]2-
mercury ki kya hoga? w/ excess KI
we get grey Hg+ [HgI4]2-
colour of the ppt and formula with potassium chromate
pbcro4 yellow , hg2cro4 red, ag2cro4 brick red
reaction with KCN
- pb(cn)2 white
- hg + hg(cn)2 soluble
- agcn white
is agcn soluble in excess of kcn?
yes, we get [ag(cn)2]-
reaction in basic medium such as naoh, koh or anything else?
- pb(oh)2 white
- hg2o ( black)
- ag2o ( brown//0
kya excess basic medium mein pb ka cation or pb(oh)2 dissolve hojata hai?
yes because [pb(oh)4]2- form hota hai , but rest mein koi change nahi
nh3 in small amount reacts to give?
- pb(oh)2 white
- hg( black) + hgo. hgnh2no3 ( white )
- ag2o brown
does lead get dissolved in excess nh3?
no only silver gets dissolved in excess ammonia since it forms ag(nh3)2+
