IDENTIFY ACID AND BASIC RADICAL PRESENT IN GIVEN MIXTURE OF SALTS

 IDENTIFY ACID AND BASIC RADICALI PRESENT

IN GIVEN MIXTURE OF SALTS

APPARATUS REQUIRED

fest tubes, beakers, funnel, conical flack, tripod stand, filter papers etc.

THEORY

Any salt is composed of two types of ions, positive and negative ions which can be also known as basic and acid radicals respectively. A mixture of three different salts may contain 3 similar or dissimilar acids & basic radicals. The presence of different kind of acid and basic radicals can be identified by conducting dry and wet tests. We do confirmatory tests for them too to confirm that there radicals are present. In case of water insoluble and colored salt mixture, we prepare Na2Co2 extract of that mixture for wet test of acid radicals.

OBSERVATIONS

Colour: Greenish

Odour: Odourless

Solubility:

: Coloured soluble in water.

Dry Tests for Acid Radicals (Anions)

• Action of dil HCI or dil H2so4

0.2 g of substance was treated in a test tube with 2-3 ml of dil. HCI, warmed gently,

Observation	Inference
No any gas evolved No effervescence No reddish browns. vapour was evolved.	Absence of CO2 from Carbonate or bicarbonat, SO2 from sulphite, So2 & S from thiosulphate, NO2 from nitrite and H2s from sulphide

•  Action of conc. H2SO4

02 g of substance was treated with 2-3 ml of com Hosoy and warmed gently,

Observation	Inference
Colorless gas evolved with pungent odour which fumes in air and produced white fumes with a glass rod moistened in Conc NH3 solution. No reddish gas & violet vapour copper turnings was added to the salt mixture with conc Hosoy & observed, no very formed brown colored.	Presence of Chloride (HCL) Absence of Br" & I Absence of nitrate

Wet Tests for Acid Radicals

Since the salt mixture formed coloured solution in water, Na, Co, extract was prepared as follows:

about 1-2 gm of given mixture was taken in a conical flask, re about 4 times of anhydrous Na2co3 was mixed to it, about 25ml water was added. A chart stem funnel was placed over the conical flask and boiled for ten minutes, cooled and filtered. That filtrate ie. Na2co2 extract was used for the test of acid radicals.

Experiment.	Observation	Inference
AgNO3 test:- about 1ml of extract was acidifted with dil HNO3, CO2 was boiled off and AgNo3 soln was added Test for sulphite:- A little Na2co3 extract was acidified with dil HCl & heated Gently Bacl2 test:- extract was treated with dil HCl & BaCl2 Solution Test for nitrate:- To the Na2co3 extract dil. H2So4 was added fill acidic &  then. freshly prepared ferrous sulphate soln was added. Then Conc. H2So4 was poured car carefully through the wall of test tube	White Ppt was formed soluble in dil NH3 soln and reappeared with Dil. HNO3 No any smell of So2 White ppt formed, Insoluble in HCL  No brown ring	Presence of Cl- Absence of So3 Presence of So4– Absence of No3-

• Reactions involved in dry test for acid radicals

Na x+H2So4 →NaHSO4 + Hx↑

2Na x + H2SO4→Na2So4 + 2H x↑ 

Reactions involved in wet test for acid redicals

 Reactions of CI-

NaCl + AgNO3 → AgCl + NaNO3

AgCl + 2NH3→ [Ag(NH3)2]Cl

[Ag(NH2 ) ]Cl + 2HNO3 → AgCl 2NH,NO3

Salt Analysis Wet Test For Basic Radicals