Question

The hydroxide of which metal ion is soluble in excess of sodium hydroxide solution :

• A. Fe3+
• B. Cr3+
• C. Sn2+
• D. Cu2+

Answer 1

Answer: (C)

Sn2+

Answer 2

Sn(OH)2 + 4OH– + H2O $\longrightarrow$ [Sn(OH)6]4–

(soluble complex)