In the brown ring test for the nitrate ion, the brown colour is due to

Question

In the brown ring test for the nitrate ion, the brown colour is due to (A) [ Fe ( H 2 O )5 NO ]2+ (B) [ Fe ( H 2 O )5 NO ]3+ (C) [ Fe ( H 2 O )5 NO 2]2+ (D) [ Fe ( H 2 O )2 NO 2]+

Tardigrade Admin · Accepted Answer

When an aqueous solution of the nitrate salt is treated with freshly prepared solution of ferrous sulphate and conc.

H_{2} S O_{4}

, a brown ring is formed on account of the formation of complex

[F e (H_{2} O)_{5} NO] S O_{4}

at the junction of two liquids.

N a N O_{3} + H_{2} S O_{4} \to N a H S O_{4} + H N O_{3}

6 F e S O_{4} + 2 H N O_{3} + 3 H_{2} S O_{4} \to 3 F e_{2} (S O_{4})_{3} + 4 H_{2} O + 2 NO

[F e (H_{2} O)_{6}] S O_{4} \cdot H_{2} O + NO \to [F e Brown ring (H_{2} O)_{5} NO] S O_{4} + 2 H_{2} O

Q. In the brown ring test for the nitrate ion, the brown colour is due to

$[F e (H_{2} O)_{5} NO]^{2 +}$

$[F e (H_{2} O)_{5} NO]^{3 +}$

$[F e (H_{2} O)_{5} N O_{2}]^{2 +}$

$[F e (H_{2} O)_{2} N O_{2}]^{+}$

Q. In the brown ring test for the nitrate ion, the brown colour is due to

[Fe(H2​O)5​NO]2+

[Fe(H2​O)5​NO]3+

[Fe(H2​O)5​NO2​]2+

[Fe(H2​O)2​NO2​]+

$[F e (H_{2} O)_{5} NO]^{2 +}$

$[F e (H_{2} O)_{5} NO]^{3 +}$

$[F e (H_{2} O)_{5} N O_{2}]^{2 +}$

$[F e (H_{2} O)_{2} N O_{2}]^{+}$