Question

Wet Tests For Basic Radicals
The basic radicals present in the given mixture may have been detected by
the "Dry tests". The final detection and confirmation of radi
are carried by taking the mixture in solution and performing with it a serves of
present, however,
reactions (wet test) in a systematic way. Thus, in "Wet Analysis", suitablereagents
are added to the solution of the mixture and the precipitate or the colour change
produced is noted. These changes are then interpreted to give the identity of
basic radicals. While the "Dry Tests" may only give a clue, the "We Tes" offer
a regular scheme for the detection and confirmation of basic radicals
While the dry tests are only preliminary, the wet analysis is comprehensive
and conclusive. Sometimes, the student may be tempted to proceed to the wet
analysis straightway. He should know that he is a criminal who wants to enter
by the back door.
Preparation of Solution
First requirement of wet analysis is preparation of solution of the original
substance in a suitable solvent.
(i) Choice of Solvent :
For the wet analysis the first necessity is to obtain a solution of the mixture
in a suitable solvent. What are the properties of the ideal solvent? First, it
must be capable of dissolving a wide range a material, so that comparatively
few will require special treatment. Second, it must react chemically with as
few substances as possible, so that there is a minimum of disturbance of the
• substance to be analysed, by its use. Third, it must be plentiful and cheap.
Fortunately, water comes near to fulfilling all these requirements. Very
many compounds are soluble in water without reacting chemically with it. Tap
water is very unsuitable for use in analysis. It always contains bicarbonates
chlorides, sulphates of calcium and magnesium and often metals in addition
Distilled water is essential for accurate work and its use is intender
whenever water is mentioned in the following pages.
Next to water, three mineral acids e.g. hydrochloric acid, nitric acid an
sulphuric acid come for selection. Sulphuric acid is altogether discarded becaus
is an oxidisio
various sulphates (Ba, Pb, Sr) are insoluble and besides this
agent, so enormous amount of sulphur will precipitate in Gr. IL
All metallic nitrates are soluble in water, so the use of nitric acid wou
not be attended by any difficulty of precipitation, but this too should be discard
as far as possible for simple reason that this is also an oxidising agent and
enormous amount of sulphur will precipitate in Gr. II.
Hydrochloric acid is free from these difficulties. Salts which are not solu
rullar coluble in hydrochloric acid except that of Ph. Hg​

Answer 1

Answer:

I also have dout in....