Acids, bases & salt preparations

What are the rules of predicting the solubility of ionic compounds?

1. Compounds of sodium, potassium and ammonium are soluble

2. All nitrates are soluble

3. All chlorides except silver and lead (II) are soluble

4. All sulfates except barium, calcium and lead (II) are soluble

5. Only sodium, potassium and ammonium carbonates are soluble

6. Only sodium, potassium and calcium hydroxides are soluble

Describe acids & bases in terms of proton transfer

Acids are proton donors

Alkalis are proton acceptors

What is produced when an acid & a base react together?

salt + water

What is produced when an acid & a metal oxide react together?

salt + water

What is produced when an acid & a metal hydroxide react together?

salt + water

What is produced when an acid & a metal carbonate react together?

salt + carbon dioxide + water

What is produced when an acid & ammonia react together?

ammonium salt

What are 5 common laboratory acids & their formulas?

Hydrochloric acid → HCl

Nitric acid → HNO₃

Sulfuric acid → H₂SO₄

Ethanoic acid (vinegar) → CH₃CO₂H

Phosphoric acid → H₃PO₄

(all acids have hydrogen in their formula because acids are hydrogen donors)

What is an alkali?

a base that is soluble in water

What substances can act as bases?

metal oxides

metal hydroxides

ammonia

Describe an experiment to prepare a pure dry sample of a soluble salt starting from an insoluble reactant (e.g. copper II oxide)

- add insoluble base to an acid

- continue to add base until there is excess base remaining to ensure that all acid has reacted

- use a filter funnel & paper to remove any unreacted base from the acid

- heat the solution with a Bunsen burner so that the water evaporates & only crystals of the salt remain

- place the salt crystals on some paper towel & leave them to dry somewhere warm

Describe an experiment to prepare a pure dry sample of a soluble salt starting from an acid & an alkali

- use a titration to calculate the exact volume of the alkali that reacts with the acid

- mix the exact volumes of the acid & the base

- warm the solution with a Bunsen burner so that water evaporates and crystals of the salt remain

- place the salt crystals on some paper towel & leave them to dry somewhere warm

Describe an experiment to prepare a pure dry sample of a soluble salt starting from 2 soluble reactants (e.g. lead II sulfate)

- mix 2 solutions of soluble reactants together

- insoluble salt crystals will form, so use a filter funnel & paper to separate them from the mixture

- wash the salt crystals with distilled water & leave them to dry