Salts

Question 1

What is the soluble rule?

Answer 1

All group 1 and ammonium salts
All nitrates
Most halides except (silver halides, lead halides)
Most sulphates except (lead sulphate, barium sulphate, calcium sulphate)
Insoluble:
Oxides, Hydroxides, Carbonates except group 1 and ammonium

Question 2

What is the insoluble base + acid method?

Answer 2

Heat the acid (increase rate of reaction)
While stirring, add base until no more will disappear (excess base to make sure all acid reacts)
Filter out the excess base (to remove it)

Question 3

Explain the crystallisation to obtain salts

Answer 3

transfer solution to an evaporating basin
heat until crystals just start to form
leave to crystallise
pick out crystals
pat dry with filter paper

Question 4

Describe method to make soluble salts

Answer 4

titration:
- Perform a titration to measure the volume of acid and alkaline that neutralise each other
- Measure out the exact volumes required and mix them together (without indicator)

Question 5

What is the point of a titration?

Answer 5

• find the concentration of unknown
• find volume of acid and alkali that exactly neutralise each other

Question 6

What is a precipitate?

Answer 6

an insoluble solid that forms in a solution

Question 7

How do you make insoluble salts by precipitation?

Answer 7

• mix solutions together in a beaker and stir with a glass rod
• filter off the precipitate (still get left over solution)
• rinse the salt with distilled water (washes of left over solution)
  can use water as salt is insoluble
• pat dry with filter paper

Question 8

Zinc Sulphate:
soluble?
salt making method?
reactants?

Answer 8

soluble: Yes
salt making method: Insoluble base
reactant 1: Zinc oxide
reactant 2: sulphuric acid

Question 9

Copper Sulphate
soluble?
salt making method?
reactants?

Answer 9

soluble: Yes
salt making method: Insoluble base
reactant 1: Copper oxide
reactant 2: Sulphuric acid

Question 10

Lead Iodide
soluble?
salt making method?
reactants?

Answer 10

soluble: No
salt making method: Precipitation
reactant 1: lead nitrate
reactant 2: potassium iodide

Question 11

Calcium Sulphate
soluble?
salt making method?
reactants?

Answer 11

soluble: No
salt making method: Precipitation
reactant 1: calcium nitrate
reactant 2: sodium sulphate