Question

Prussian blue is formed when

A. ferrous sulphate reacts with $$FeC{l_3}$$
B. ferric sulphate reacts with $$N{a_4}\left[ {Fe{{\left( {CN} \right)}_6}} \right]$$  
C. ferrous ammonium sulphate reacts with $$FeC{l_3}$$
D. ammonium sulphate reacts with $$FeC{l_3}$$
Answer :   ferric sulphate reacts with $$N{a_4}\left[ {Fe{{\left( {CN} \right)}_6}} \right]$$
Solution :
When the sodium fusion extract is added with $$FeC{l_3}$$  and then the resulting solution is acidified with dilute hydrochloric acid, the appearance of Prussian blue colouration confirms the presence of nitrogen in the organic compound.
$$Na + C + N \to NaCN$$
$$FeS{O_4} + 2NaCN \to $$     $$Fe{\left( {CN} \right)_2} + N{a_2}S{O_4}$$
$$Fe{\left( {CN} \right)_2} + 4NaCN \to $$     $$N{a_4}\left[ {Fe{{\left( {CN} \right)}_6}} \right]$$
$$3N{a_4}\left[ {Fe{{\left( {CN} \right)}_6}} \right] + 4FeC{l_3} \to $$      $$\mathop {F{e_4}{{\left[ {Fe\left( {C{N_6}} \right)} \right]}_3}}\limits_{{\text{Prussian blue}}} + 12NaCl$$

Releted MCQ Question on
Inorganic Chemistry >> Qualitative Analysis

Releted Question 1

The ion that cannot be precipitated by both $$HCl\,{\text{and}}\,{H_2}S$$    is

A. $$P{b^{2 + }}$$
B. $$C{u^ + }$$
C. $$A{g^ + }$$
D. $$S{n^{2 + }}$$
Releted Question 2

Which one among the following pairs of ions cannot be separated by $${H_2}S$$  in dilute hydrochloric acid?

A. $$B{i^{3 + }},S{n^{4 + }}$$
B. $$A{l^{3 + }},H{g^{2 + }}$$
C. $$Z{n^{2 + }},C{u^{2 + }}$$
D. $$N{i^{2 + }},C{u^{2 + }}$$
Releted Question 3

An aqueous solution contains $$H{g^{2 + }},Hg_2^{2 + },P{b^{2 + }}\,{\text{and}}\,C{d^{2 + }}.$$
The addition of $$HCl\left( {6N} \right)$$   will precipitate:

A. $$H{g_2}C{l_2}\,{\text{only}}$$
B. $$PbC{l_2}\,{\text{only}}$$
C. $$PbC{l_2}\,{\text{and}}\,H{g_2}C{l_2}$$
D. $$PbC{l_2}\,{\text{and}}\,HgC{l_2}$$
Releted Question 4

Identify the correct order of solubility of $$N{a_2}S,\,CuS\,{\text{and}}\,ZnS$$     in aqueous medium

A. $$CuS > ZnS > N{a_2}S$$
B. $$ZnS > N{a_2}S > CuS$$
C. $$N{a_2}S > CuS > ZnS$$
D. $$N{a_2}S > ZnS > CuS$$

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