Chapter 20, Problem 20.68SP

Interpretation Introduction

Interpretation:

Among the given chromium hydroxide which is amphoteric, the net ionic equation of that chromium hydroxide with hydroxide ion, oxidation sate of the chromium and the color of the product should be determined.

Concept introduction:

A substance which is basic as well as acidic in nature is recognized as an amphoteric substance. In other terms an amphoteric substance which will react with both bases and acids.
"Chromium(III) hydroxide" is a simplestmethod of to name the neutral complex compound like $[\text{Cr}{\left(\text{H2O}\right)}_3{\left(\text{OH}\right)}_3]$. As we have seen that, it reacts with bases (hydroxide ions) to yield ${\left[\text{Cr}\left(\text{OH}\right)\text{6}\right]}^{3-}$. It reacts with acids (hydrogen ions) as well to yield ${\left[\text{Cr}\left(\text{OH}\right)\text{6}\right]}^{3+}$.

This is a decentillustration of amphoteric nature.Other illustrations of amphoteric substances are aluminum hydroxide and zinc hydroxide.