Question

Which of the following metals in solution forms a precipitate with $NaOH,$ which is not soluble in an excess of the base?

• A. Fe
• B. Sn
• C. Pb
• D. Zn

Answer 1

Answer: (A)

Iron (Fe) metal in solution forms a red brown precipitate with $NaOH$ and this precipitate is not soluble in an excess of the base. $FeC{l}_3+3NaOH\to \underset{\begin{array}{c}\text{ferric}\text{hydroxide}\\ (redbrownppt.)\end{array}}{Fe{(OH)}_3}+3NaCl$ While the precipitate of Sn, Pb, Zn and all hydroxides are soluble in the excess of base.