Question

Ions \[{S^{2 - }}\]and \[S{O_{}}_3^{2 - }\] can be distinguished by using:
A.\[{(C{H_3}COO)_2}Pb\]
B.\[N{a_2}\left[ {Fe{{\left( {CN} \right)}_5}NO} \right]\]
C.Both A and B
D.None of these

Answer 1

Hint: When we talk about the given reagents we conclude that on reaction the sulphide will give black ppt. with first option and violet colour compound formation with second one whereas the sulphite ions give white ppt. with first and colour difference with the second one.

Complete step-by-step answer:When we talk about the sulphide ions we come to know that it is a divalent inorganic anion which is obtained by the removal of protons. Further talking more about it we come to know that the ions are corrosive in nature. When we generally talk about the metal sulphides we come to know that many of the metal sulphides are insoluble in water.
Also there in the question we need to discuss about the other molecule that is sulphite. We come to know that they can be further described as three equivalent resonance structures. When we further discuss its structure in detail we come to know that it is doubly bonded to only one of the three oxygen atoms and further singly bonded to the other two.
 Discussing more on it with the options provided we can say that both the reagents can be used for the distinguishing.
Test with \[{(C{H_3}COO)_2}Pb\] we come to know that:
\[{S^{2 - }} + {(C{H_3}COO)_2}Pb \to PbS \downarrow + 2C{H_3}CO{O^ - }\] in this reaction the black precipitate of lead sulphide is formed.
\[SO_3^{2 - } + {(C{H_3}COO)_2}Pb \to PbS{O_4} \downarrow + 2C{H_3}CO{O^ - }\] when the reaction is further carried out with the sulfite ion the white precipitate of lead sulphate is formed.
Further testing it with the second reagent
\[{S^{2 - }} + N{a_2}\left[ {Fe{{\left( {CN} \right)}_5}NO} \right] \to N{a_4}\left[ {Fe{{\left( {CN} \right)}_5}NOS} \right]\] in this reaction a violet compound is formed.
\[SO_3^{2 - } + N{a_2}\left[ {Fe{{\left( {CN} \right)}_5}NO} \right] \to N{a_4}\left[ {Fe{{\left( {CN} \right)}_5}NOS{O_3}} \right]\]When this reaction is carried out this is formed.
we concluded that the option C is correct that means the both the options reagents can help us to distinguish between the two.

Note:It should be noted here that when the sulphide is combined with hydrogen it is used to produce sulphur. Further sulphites are used as an additive to maintain food colour.