Assertion: Potassium can be used in the Lassaigne test.
Reason: Potassium reacts vigorously.

Identify the binary mixture$(s)$ that can be separated into individual compounds by differential extraction,as shown in the given scheme.
$(A)$ $C_6H_5OH$ and $C_6H_5COOH$
$(B)$ $C_6H_5COOH$ and $C_6H_5CH_2OH$
$(C)$ $C_6H_5CH_2OH$ and $C_6H_5OH$
$(D)$ $C_6H_5CH_2OH$ and $C_6H_5CH_2COOH$

Match column $-I$ and column $-II$ with the correct relation:

Column $-I$	Column $-II$
$(i).$ Prussian blue	$(a).$ Presence of phosphorus
$(ii).$ Yellow precipitate	$(b).$ Presence of sulphur
$(iii).$ Purple solution	$(c).$ Presence of nitrogen
$(iv).$ Black precipitate	$(d).$ Presence of chlorine

During the fusion of an organic compound with sodium metal,the nitrogen present in the organic compound is converted into:

In the Lassaigne sodium fusion test,$N$ and $S$ of an organic compound are converted into:

Three students,Manish,Ramesh,and Rajni were determining the extra elements present in an organic compound given by their teacher. They prepared the Lassaigne's extract $(L.E.)$ independently by the fusion of the compound with sodium metal. Then they added solid $FeSO_4$ and dilute sulphuric acid to a part of the Lassaigne's extract. Manish and Rajni obtained prussian blue colour,but Ramesh got red colour.
Ramesh repeated the test with the same Lassaigne's extract,but again got red colour only. They were surprised and went to their teacher and told him about their observation. Teacher asked them to think over the reason for this. Can you help them by giving the reason for this observation? Also,write the chemical equations to explain the formation of compounds of different colours.