IN SALT ANALYSIS
wat r d gp. detecting & confirmatory test for
1) Bi3+
2)Cr3+
3)Ca2+
1For Ca2+
To the original solution add solid NH4Cl , NH4OH and (NH4)2CO3 solution.
White ppt. is formed
Dissolve a part of white ppt. in dil. acetic acid . Boil off CO2
Add ammonium oxlate to the above solution .
white ppt. confirms Ca2+
Or you can perform flame test with the salt
brick red flame confirms -Ca2+
1The Bi3+ that precipitates in an ammoniacal solution to produce
white bismuth hydroxide is dissolved and confirmed with the addition oà freshly prepared sodium stannite, Na2Sn(OH)4, in a basic solution.
The Bi3+ ion is reduced to black bismuth metal, confirming the presence of bismuth inthe sample.
24for Cr3+
ppt of Cr3+ is soluble in NaOH+Br2 water and addn of BaCl2 gives yellow ppt.
1for Bi3+...
first clue is : wen water+HCl is added to the filtrate of group 1 , even before addition of H2S gas, there is a white turbidity ..
this turbidity disappears on addition of dil.HCl ..
this is itself a confirmatory test for Bi3+ .
BiCl3 + H2O -> BiOCl [turbidity] -----------+HCl--------> BiCL3
adding to these are those given by Ankit.
11CHECK THIS OUT
http://targetiit.com/iit_jee_forum/posts/important_information_2774.html
