Which one is correct group reagent for group cations?

CHEMISTRY · Single correct · GCSE · Chemistry · Chemical Analysis · Chemical Analysis

Problem

Which one is correct group reagent for group cations? (1)

\text{Mn}^{2+}

\text{Co}^{2+}

\text{Zn}^{2+}

\text{Ni}^{2+}

;

\text{HCl} + \text{H}_2\text{S}

(2)

\text{Mn}^{2+}

\text{Co}^{2+}

\text{Zn}^{2+}

\text{Ni}^{2+}

; dil.

\text{HCl}

(3)

\text{Mn}^{2+}

\text{Co}^{2+}

\text{Zn}^{2+}

\text{Ni}^{2+}

;

\text{NH}_4\text{Cl} + \text{NH}_4\text{OH}

(4)

\text{Mn}^{2+}

\text{Co}^{2+}

\text{Zn}^{2+}

\text{Ni}^{2+}

;

\text{NH}_4\text{Cl} + \text{NH}_4\text{OH} + \text{H}_2\text{S}