Question
A blue colouration is not obtained when
A.
ammonium hydroxide dissolves in copper sulphate.
B.
copper sulphate solution reacts with $${K_4}\left[ {Fe{{\left( {CN} \right)}_6}} \right].$$
C.
ferric chloride reacts with sod. ferrocyanide.
D.
anhydrous $$CuS{O_4}$$ is dissolved in water.
Answer :
copper sulphate solution reacts with $${K_4}\left[ {Fe{{\left( {CN} \right)}_6}} \right].$$
Solution :
$$2CuS{O_4} + {K_4}\left[ {Fe{{\left( {CN} \right)}_6}} \right] \to \mathop {C{u_2}\left[ {Fe{{\left( {CN} \right)}_6}} \right] + 2{K_2}S{O_4}}\limits_{{\text{Chocolate ppt}}{\text{.}}} $$