Question

The correct option(s) to distinguish nitrate salts of $M{n}^{2+}$ and $C{u}^{2+}$ taken separately is (are)

• A. $M{n}^{2+}$ shows the characteristic green colour in the flame test
• B. Only $C{u}^{2+}$ shows the formation of precipitate by passing $H_{2}S$ in acidic medium
• C. Only $M{n}^{2+}$ shows the formation of precipitate by passing $H_{2}S$ in faintly basic medium
• D. $C{u}^{2+}/Cu$ has higher reduction potential than $M{n}^{2+}/Mn$ (measured under similar conditions)

Answer 1

Answer: (B), (D)

(A) $C{u}^{+2}$ and $M{n}^{+2}$ both gives green colour in flame test and cannot distinguished.
(B) $C{u}^{+2}$ belongs to group-II of cationic radical will gives ppt. of CuS in acidic medium.
(C) $C{u}^{+2}$ and $M{n}^{+2}$ both form ppt. in basic medium.
(D) $C{u}^{+2}/Cu=+0.34V(SRP)$
$M{n}^{+2}/Mn=-1.18V(SRP)$