5.3 MAKING SALTS

Question 1

What soluble salts are made by the insoluble base method

Answer 1

Those without Na, NH4, or K ions

Question 2

What must the base reactant be when making a soluble salt with the insoluble base method

Answer 2

Insoluble

Question 3

How to carry out the insoluble base method for making a soluble salt

Answer 3

• Heat the acid - Hot acid has more kinetic energy, so reacts faster with the base
• Add the base till no more will dissolve and stir - the base is in excess so we know all the acid has been used up
• Filter out excess base
• CRYSTALLISE

Question 4

How to perform a crystallisation for a soluble salt

Answer 4

• Heat solution until crustals start to form - solution becomes saturated
• Allow solution to cool in evaporating basin - lowers solubility of salt
• Filter out crystals - removes them from excess salt solution in basin
• Dry crystals by dabbing with filter paper - removes last traces of water

Question 5

When is the titration method used for making a soluble salt

Answer 5

When alkalis contain Na, K, or NH ions, as you wouldn’t be able to filter them out, like the insoluble base method

Question 6

How to carry out the titration method for making a soluble salt

Answer 6

• Perform a titration to measure the volumes of acid and alkali that neutralise each other (with an indicator)
• Repreat without an indicator, and use the burette to add exactly the right amount for neutralisation
• CRYSTALLISE

Question 7

What is a precipitate

Answer 7

An insoluble solid that forms inside a solution

Question 8

How is a precipitate formed

Answer 8

Mixing ions up, and seeing insoluble compounds form

Question 9

What type of substance is used to make an insoluble salt

Answer 9

Mixing solutions

Question 10

What are spectator ions

Answer 10

Ions that aren’t involved in making a percipitate and remain soluble in the solution

Question 11

How to write an ionic equation

Answer 11

Just write the ions involving the precipitation

Question 12

How to write an ionic equation

Answer 12

Just write the ions involving the precipitation

Question 13

How to prepare an insoluble salt

Answer 13

• Filter out salt precipitate
• Rinse the salt with water, to wash off traces of leftover solution
• Dry the salt by dabbing it with filter paper - removes the last traces of water