Table 7.1

Question 1

Describe the solubility of nitrates (NO₃⁻).

Answer 1

Nitrates are always soluble. Mnemonic: ‘Nitrates Never Not Dissolve.’

Question 2

Explain the solubility of chlorides and their exceptions.

Answer 2

Most chlorides are soluble, except for Silver (Ag⁺), Lead (Pb²⁺), and Mercury (Hg₂²⁺). Mnemonic: ‘SLM’.

Question 3

Define the solubility of sulfates (SO₄²⁻) and their exceptions.

Answer 3

Most sulfates are soluble, except for Barium (Ba²⁺), Lead (Pb²⁺), and Calcium (Ca²⁺). Mnemonic: ‘BPC’.

Question 4

How soluble are hydroxides (OH⁻) and what are the exceptions?

Answer 4

Hydroxides are mostly insoluble, except for Sodium Hydroxide (NaOH) and Potassium Hydroxide (KOH) which are soluble, and Barium Hydroxide (Ba(OH)₂) and Calcium Hydroxide (Ca(OH)₂) which are slightly soluble. Mnemonic: ‘Hydroxides Hide.’

Question 5

Identify the ions that make almost everything soluble.

Answer 5

Group 1 ions (Na⁺, K⁺) and Ammonium (NH₄⁺). Mnemonic: ‘1A + Ammonium = Always Aqueous.’

Question 6

Discuss the solubility of sulfides, carbonates, and phosphates.

Answer 6

Sulfides, carbonates, and phosphates are generally insoluble, but they dissolve in the presence of Sodium (Na⁺), Potassium (K⁺), or Ammonium (NH₄⁺). Mnemonic: ‘SCP = Sink, unless with Na/K/NH₄.’