Aim to detect two acidic and two radicals from the given misture
Answers
Answer:
Dry Test :
Borax Bead Test:
It can be performed for the colored salts.
On heating, the fission of borax takes place and it will lose water of crystallization.
After melting, it will form colorless liquid which then forms a transparent bead comprising of boric anhydride and sodium metaborate.
Na_{2} B_{4} O_{7} . 10 H_{2}O - - - - - - - - > Na_{2} B_{4} O_{7} + 10 H_{2}ONa
2
B
4
O
7
.10H
2
O−−−−−−−−>Na
2
B
4
O
7
+10H
2
O
Na_{2} B_{4} O_{7} - - - - - - - - > B_{2} O_{3} + 2 Na B O_{2}Na
2
B
4
O
7
−−−−−−−−>B
2
O
3
+2NaBO
2
As anhydride of boric will be non-volatile.
When reacted with colored salt , a colored bead of metal carbonate will be formed.
Wet Test for Acid radicals :
When salt is mixed with dilute sulfuric acid and with concentrated sulfuric acid.
The inference will be done on the basis of the gas evolved.
1. The evolving colorless CO₃²⁻ gas will turn the lime water milky.
2. The brown gas NO₂⁻ : Addition of KI and starch solution will turn the solution into blue color.
3. Smell of S₂⁻ : This will turn lead acetate paper color black with the smell of rotten eggs .
4.Pungent SO₃⁻ : This will turns acidified potassium dichromate solution colorless.
5. Smell of CH3COO⁻ : aqueous + neutral FeCl2. It will give blood red color to the solution.
6. On heating:
white/Yellow S₂O₃²⁻ + AgNO3 (white ppt) ---> black turbidity
7. Colorless Cl- addition:
MnO2 and heat with the evolution of pungent gas with white fumes and pale green color gas will be evolved .
8. Reddish brown Br- :
Addition of MnO2 and then heating, fumes of brown gas will be evolved.
9. Violet I- :
It will convert starch paper blue.
Wet Test for Basic Radical
I Ag+, Hg2+, Pb2+ dilute hydrochloric acid - - - -> for Cl
II Cu2+,Cd2+,Pb2+,Hg2+ H2S gas + HCl Sulphides Bi3+,As3+, Sb3+ Sn2+
III Al3+,Cr3+, Fe3+, NH4OH + NH4Cl - - - - > for OH.
Iv Zn2+, Ni2+,Mn2+Co3+ H2S in Sulfides ammoniacal medium
V Ca2+,Ba2+ Sr2+ (NH4)2CO3 +NH4Cl - - - - - -> for Carbonates
VI Mg2+ ,Na+,K+ NH4OH , Na2HPO4 - - - - - -> for Mg2+