Question

What will be the colour of the solution when $Mn(OH{)}_2$ is treated with concentrated $HN{O}_3$ and sodium bismuthate (or red lead or lead dioxide)?

• A. Yellow
• B. Purple
• C. Green
• D. Blue

Answer 1

The correct option is B Purple

when sodium bismuthate $\left(NaBi{O}_3\right)$ is added to a cold solution of manganeses $\left(II\right)$ ions in dilute nitric acid

or in dilute sulphuric acid, the mixturre stirred and excess reragent filtered off, a violet red (or purple)

solution of permanganatee is produced.

$2M{n}^{2+}+5NaBi{O}_3+14H^{+}\to 2Mn{O}_4^{-}+5B{i}^{3+}+5N{a}^{+}+7H_{2}O$

$purplecolour$