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7.3 Making salts from solutions Soluble or insoluble? What do these terms mean? July 20, 2022 Fertilisers Water Treatment

7.3 Making salts from solutions Soluble or insoluble? What do these terms mean? 17 September 2015 Fertilisers Water Treatment

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Page 1: 7.3 Making salts from solutions Soluble or insoluble? What do these terms mean? 17 September 2015 Fertilisers Water Treatment

7.3 Making salts from solutions

Soluble or insoluble? What do these terms mean?

April 19, 2023

Fertilisers

Water Treatment

Page 2: 7.3 Making salts from solutions Soluble or insoluble? What do these terms mean? 17 September 2015 Fertilisers Water Treatment

7.3 Making salts from solutions

• Indicators are needed to check producing a soluble salt from an alkali and acid.

• Insoluble salts produce a precipitate when reacting two solutions.

• Precipitation is an important way of removing some substances from waste water.

April 19, 2023

Soluble = Able to dissolve in a solvent.

Insoluble = Unable to dissolve in a solvent.

Precipitate = A solid material produced from a solution.

Page 3: 7.3 Making salts from solutions Soluble or insoluble? What do these terms mean? 17 September 2015 Fertilisers Water Treatment

Acid + alkali

A neutralisation reaction is where an acidacid reacts with a alkalialkali to produce a neutral solution of a a saltsalt and waterwater.

1 2 14131211109876543

Increasingly acid Increasingly alkali

sodium hydroxidepH 14

hydrochloric acidpH 1

neutralisation

sodium chloridepH 7

Salt

alkalalkalii

How can the salt be separated from the water?

Page 4: 7.3 Making salts from solutions Soluble or insoluble? What do these terms mean? 17 September 2015 Fertilisers Water Treatment

Neutralisation reactions: hydroxides

Each OH- ion reacts with one H+ ion.

Reaction with hydroxides: H+ + OH- H2O

Eg. Potassium +hydrochloric water + potassium hydroxide acidchloride

KOHOH + H HCl HH22OO + KClEg. Calcium + sulphuric water + calcium hydroxide acid sulphate

Ca(OHOH)22 + HH22SO4 2H2H22OO + CaSO4

Water can be evaporated to leave the salt behind.

Page 5: 7.3 Making salts from solutions Soluble or insoluble? What do these terms mean? 17 September 2015 Fertilisers Water Treatment

Insoluble Salts

• A precipitation reaction leaves behind a solid material. E.g.Lead Nitrate + Sodium Chloride → Lead Chloride + Sodium

NitratePb(NO3)2 (aq) + 2NaCl (aq) → PbCl2 (s) + 2NaNO3 (aq)

Practical

1.Add sodium chloride to lead nitrate and stir.

2.Filter the precipitate.

3.Wash and dry precipitate. Place on a watch glass.

4.Write down what the Lead Chloride looks like.

Page 6: 7.3 Making salts from solutions Soluble or insoluble? What do these terms mean? 17 September 2015 Fertilisers Water Treatment

Filtering

Page 7: 7.3 Making salts from solutions Soluble or insoluble? What do these terms mean? 17 September 2015 Fertilisers Water Treatment

7.3 Making salts from solutions

• Indicators are needed to check producing a soluble salt from an alkali and acid.

• Insoluble salts produce a precipitate when reacting two solutions.

• Precipitation is an important way of removing some substances from waste water.

April 19, 2023

Soluble = Able to dissolve in a solvent.

Insoluble = Unable to dissolve in a solvent.

Precipitate = A solid material produced from a solution.