V Chemistry - Acids, bases and salts

Acids _____ H+ ions

Release

Bases _____ H+ ions

Accept

What can act as bases?

Metal oxides, metal hydroxides, ammonia

What are bases that are soluble in water?

Alkali

Experiment to prepare a pure, dry sample of a soluble salt from an insoluble reactant

Filtration:

• Warm the acid in a beaker (sulfuric)

• Using a spatula, add reactant into the acid and stir

• Keep adding copper oxide and stirring until no more disappears

• Filter the mixture

• Warm the filtrate to evaporate around half of the water

• Leave the solution to cool

• Filter the crystals out of this solution

• Leave the crystals in a warm place to dry

Experiment to prepare a pure, dry sample of a soluble salt from an acid and an alkali

Titration:

• Measure alkali in a glass pipette

• Add alkali to conical flask

• Add acid to burette

• Take the initial volume of acid

• Titrate until neutralisation

• Repeat until concordant results

• Repeat without indicator

• Crystalise solution

Experiment to prepare a pure, dry sample of a insoluble salt from two soluble reactants

Precipitation:

• Mix the two solutions

• Stir well and leave the mixture until a precipitate forms

• Filter the mixture using two pieces of filter paper

• Wash the precipitate using distilled water

• Transfer the precipitate to a watch glass and leave it in a warm place