Making salts

Excess Base Method (Soluble Salt) (6)

• M1: Add Magnesium Oxide to dilute sulfuric acid.

• M2: Warm/Heat the acid (to increase rate of reaction).

• M3: Add oxide in excess / stir until no more dissolves.

• M4: Filter to remove unreacted/excess magnesium oxide.

• M5: Heat filtrate to point of crystallization / saturation point.

• M6: Test for saturation by seeing if crystals form on a cold glass rod.

• M7: Leave to cool (so solubility decreases and crystals grow).

• M8: Filter crystals from the remaining mother liquor.

• M9: Dry between filter papers / in a warm oven (do not overheat).

Precipitation Method (Insoluble Salt) (6)

• M1: Mix aqueous silver nitrate and aqueous sodium chloride (must state solutions).

• M2: Stir the mixture.

• M3: Filter the mixture to collect the precipitate as the residue.

• M4: Wash the residue.

• M5: Use distilled water for washing.

• M6: Continue washing until no more soluble ions (nitrates) remain.

• M7: Dry the precipitate.

• M8: Use a warm oven / pat dry with filter paper.

Titration Method (SPA Salts) (6)

• M1: Use a pipette to measure a fixed volume of alkali into a conical flask.

• M2: Add a named indicator (e.g., methyl orange/phenolphthalein).

• M3: Add acid from a burette slowly/dropwise near the end-point.

• M4: Record the volume (titre) of acid added when color changes.

• M5: Repeat using the same volumes without indicator.

• M6: Heat the resulting solution to the point of crystallization.

• M7: Allow to cool slowly to form crystals.

• M8: Filter crystals and dry them.

Ionic Bond (2)

• M1: Electrostatic attraction (Must use this term)

• M2: Between oppositely charged ions.

Metallic Bond (3)

• M1: Electrostatic attraction (Must use this term)

• M2: Between positive (metal) ions (or cations)...

• M3: ...and delocalised electrons.

Covalent bond (3)

• M1: Electrostatic attraction (Must use this term)

• M2: Between a shared pair of electrons...

• M3: ...and the nuclei (plural) of the bonded atoms.

intermolecular forces only refers to

Simple molecular

Zinc or aluminium

• they both redissolve in NaOH

• aluminium doesn’t redissolve in NH₃

Obtaining a Soluble Salt (Crystallisation) (4)

• M1: Heat/Evaporate the solution/filtrate until it is saturated / to the crystallisation point.

• M2: Check for saturation by dipping a cold glass rod into the solution (crystals should form on the rod).

• M3: Leave the solution to cool (slowly) to allow crystals to grow.

• M4: Filter the crystals and dry them between filter papers / in a warm oven.

Obtaining an Insoluble Salt (4)

• M1: Filter the reaction mixture to collect the precipitate as the residue.

• M2: Wash the residue/precipitate.

• M3: Use distilled water to remove soluble impurities/spectator ions.

• M4: Dry the precipitate in a warm oven / between filter papers / to constant mass.