NH 4 SCN can be used to test one or more out of Fe 3+, Co 2+, Cu 2+

Question

NH 4 SCN can be used to test one or more out of Fe 3+, Co 2+, Cu 2+ (A) Fe 3+ only (B) Co 2+, Cu 2+ (C) Fe 3+, Cu 2+ (D) All of these

Tardigrade Admin · Accepted Answer

Cu 2++2 SCN - arrow underset textblackCu ( SCN )2 downarrow xrightarrowΔ underset textblack whiteCuSCN downarrow+( SCN )2 Fe 3++ SCN - arrow underset textred[ Fe ( SCN )]2+ Co 2++ SCN - arrow underset textblue[ Co ( SCN )4]2-

Q. $N H_{4} SCN$ can be used to test one or more out of $F e^{3 +}, C o^{2 +}, C u^{2 +}$

$F e^{3 +}$ only

$C o^{2 +}, C u^{2 +}$

$F e^{3 +}, C u^{2 +}$

All of these

$C u^{2 +} + 2 SC N^{-} \to black C u (SCN)_{2} ↓ Δ black white C u SCN ↓ + (SCN)_{2}$
$F e^{3 +} + SC N^{-} \to red [F e (SCN)]^{2 +}$
$C o^{2 +} + SC N^{-} \to blue [C o (SCN)_{4}]^{2 -}$

Q. NH4​SCN can be used to test one or more out of Fe3+,Co2+,Cu2+

Fe3+ only

Co2+,Cu2+

Fe3+,Cu2+