Chemistry - Salts

Question 1

What are the soluble salts?

Answer 1

All sodium, potassium, ammonium salts, and nitrates. All chlorides, bromides and iodides except lead and silver. All sulfates except lead, barium and calcium.

Question 2

What are the insoluble salts?

Answer 2

All carbonates and hydroxides except sodium, potassium and ammonium.

Question 3

What is method 1 to prepare salts soluble in water?

Answer 3

For water-soluble salts, excluding sodium, potassium and ammonium. Not for highly reactive/unreactive metals.
→ Fill half a beaker with the acid
→ Stir constantly and keep adding EXCESS insoluble solid until no more zinc dissolves or no more effervescence is observed
→ Filter to remove excess unreacted insoluble solid and collect the filtrate
→ Filtrate will be crystallized to obtain the final product

Question 4

What is the method used for two soluble reactants?

Answer 4

Titration.
Acid + alkali → salt + water
Acid + soluble carbonate (SPA) → soluble salt + water + carbon dioxide
Recall the titration procedure, then use the recorded about of acid in a new experiment if the pure salt crystal is needed.

Question 5

What is the method used to prepare an insoluble solid?

Answer 5

Precipitation. solution AB + aq. solution XY → ins. salt AY + aq. solution XB. Allows the ions to exchange with each other. Determine the precipitate based on which is an insoluble (salt) solid.
–> Pour about 50cm3 of limiting reagent into a beaker, add excess reagent and while stirring until no more precipitate forms.
–> Filter the mixture to obtain the crystals, and use the crystallization cleaning methods

Question 6

How to convert an insoluble substance to soluble for precipitation?

Answer 6

Use method 1 of salt preparation: Add excess insoluble substance into the other substance. Once reacted (no more effervescence produced), filter out the excess insoluble substance. It can now be used for the precipitation reaction.

Question 7

What are the rules for writing ionic equations?

Answer 7

• For soluble salt equations, acid and alkali solutions, break up the species into its ions
• If the salt is insoluble in the solid state, do not split it into its ions
• For solids, liquids, and gases, leave it as it is
• Cancel out the common terms on both sides