inorganic chem; reaction of ions in aqueous solution

Question 1

Metal-aqua complex formed when…

Answer 1

… a transition metal compound is added to water

Question 2

A … pair on the … allows bond to be formed

Answer 2

… lone
… O2

Question 3

Metal-aqua ions are … when in solution

Answer 3

…acidic

Question 4

What factor affects how acidic a metal-aqua solution?

Answer 4

The charge of the ion

Question 5

What ion makes a solution acidic?

Answer 5

H3O+

Question 6

Why are 2+ complex ions not acidic?

Answer 6

As they dissociate weakly

Question 7

Why do 3+ metal-aqua complex ions dissociate more readily than 2+ complex ions?

Answer 7

• As 3+ metal ion have a higher charge density than 2+ ions — 3+ ions have a larger charge & are smaller
• 3+ ions are more polarising, they attract more e- in the O-H bond weakening it
• Increases the chance of H+ ions being released
• So 3+ ions form acidic solutions

Question 8

Further hydrolysis of metal-aqua ions using … form…

Answer 8

…OH- ions
…insoluble metal hydroxides

Question 9

What type of reaction occurs when 3+ metal-aqua complex ions are hydrolysed?

Answer 9

An equilibrium reaction – this where ions are hydrolysed further

Question 10

What happens if OH- ions are added?

Answer 10

Equilibrium shifts to the right – H3O+ ions are removed

Question 11

What is formed when 3+ metal-aqua complex ions are hydrolysed further?

Answer 11

A neutral complex that is solid & forms a precipitate in solution

Question 12

What occurs when 2+ metal-aqua complex ions are hydrolysed further?

Answer 12

• 2 water ligands are deprotonated
• forming a neutral complex

Question 13

Metal hydroxides can act as a … or a … , so they are …

Answer 13

…acid
…base
…amphoteric

Question 14

Why can metal hydroxides dissolve in both excess acid & base?

Answer 14

As they are amphoteric