Chapter 20, Problem 20.58SP

Interpretation Introduction

Interpretation:

From the given set of chromium hydroxide compounds the amphoteric compound has to be identified. The balanced net ionic equation for the reaction of amphoteric compound with hydroxide ion then the oxidation state and color of the product should be determined.

Concept Introduction:

Lewis acid: The chemical species which accepts pair of electrons are termed as Lewis acid.

Lewis base: The chemical species which donates pair of electrons are termed as Lewis base.

Acid: The substances that donate ${\text{H}}^{\text{+}}$ are termed as acids.

Base: The substances that accept ${\text{H}}^{\text{+}}$ or donate ${\text{OH}}^{\text{-}}$ are termed as base.

Amphoteric: They are compounds or ions that react with both acid and base. Example for amphoteric is ${\text{Al}}_{\text{2}}{\text{O}}_3$.

Ionic equation is an equation in which ions are explicitly shown.

Spectator ions are the ion that appears unchanged on both sides of a reaction arrow.

Net ionic equation is the chemical equation for a reaction which lists only those species participating in the reaction.

To write the net ionic equation, steps mentioned below must be followed.

1. 1. Write the balanced molecular equation
2. 2. Write the ionic equation showing the strong electrolytes completely dissociated into cations and anions.
3. 3. Cancel the spectator ions on both sides of the ionic equation.
4. 4. Check that charges and number of atoms are balanced in the net ionic equation.