Metal Aqua-Ions

Question 1

Explain why Co^2+ solution will be less acidic than a solution of Al^3+ ions dissolved in water.

Answer 1

• Al^3+ has a higher charge density than Co^2+
• Al^3+ ions are more polarising than Co^2+ Ions
• More polarising power means they attract electrons from oxygen atoms of coordinated water molecules more strongly
• Weakening O-H bond
• Hydrogen ion will be released
• More Hydrogen ions, more Acidic solution