Question

Match the items of Column I with Column II and choose the correct option from the codes given below.

Column I(Test for element)		Column II(Products involved in the chemical reaction)
A	Test for nitrogen	1	$ \left( NH _{4}\right)_{3} PO _{4} \cdot 12 MoO _{3} $ Ammonium phosphomolybdate
B	Test for sulphur	2	$ Fe _{4}\left[ Fe ( CN )_{6}\right]_{3} \cdot x H _{2} O $ Prussian blue
C	Test for both nitrogen and sulphur	3	$Ag X$
D	Test for halogens	4	$ [ Fe ( SCN )]^{2+} $ Blood red
E	Test for phosphorus	5	$PbS$ Black

• A. $A - (1), B - (2), C - (3), D - (4), E - (5)$
• B. $A - (2), B -(5), C - (4), D - (3), E - (1)$
• C. $A - (5), B - (3), C - (4), D - (2), E - (1)$
• D. $A - (4), B - (2), C - (3), D - (1), E - (5)$

Answer 1

Answer: (B)

The correct match is
$A \rightarrow 2, B \rightarrow 5, C \rightarrow 4, D \rightarrow 3, E \rightarrow 1$
A. Test for nitrogen $: 6 CN ^{-}+ Fe ^{2+} \longrightarrow\left[ Fe ( CN )_{6}\right]^{4-}$
$3\left[ Fe ( CN )_{6}\right]^{4-}+4 Fe ^{3+} \xrightarrow{x H _{2} O } \underset{\text{Prussian blue}}{Fe _{4}\left[ Fe ( CN )_{6}\right]_{3} \cdot x H _{2} O}$
B. Test for sulphur : $S ^{2-}+ Pb ^{2+} \longrightarrow \underset{\text{Black}}{PbS}$
$S ^{2-}+\left[ Fe ( CN )_{5} NO \right]^{2-} \longrightarrow \underset{\text{Violet}}{\left[ Fe ( CN )_{5} NOS ^{4-}\right]}$
C. Test for both nitrogen and sulphur :
$Na + C + N + S \longrightarrow NaSCN$
$Fe ^{3+}+ SCN ^{-} \longrightarrow \underset{\text{Blood red}}{[Fe ( SCN )]^{2+}}$
$NaSCN +2 Na \longrightarrow NaCN + Na _{2} S$
D. Test for halogen $: X^{-}+ Ag ^{+} \longrightarrow Ag X$
E. Test for phosphorus :
$Na_3PO_4 + 3HNO_3 \rightarrow H_3PO_4 + 3NaNO_3$
$H_3PO_4 + \underset{\text{Ammonium molybdate}}{12(NH_4)_2MoO_4} + 21 HNO_3 \rightarrow$
$\underset{\text{Ammonium phosphomolybdate}}{(NH_4)_3PO_4 \cdot 12MoO_3 } + 21NH_4NO_3 + 12H_2O$