3.05 Making insoluble salts

Question 1

Soluble or insoluble:

Common salts of sodium, potassium and ammonium

Answer 1

Soluble

Question 2

Soluble or insoluble:

Nitrates

Answer 2

Soluble

Question 3

Soluble or insoluble:

Common chlorides

Answer 3

Soluble

EXCEPT: silver chloride and lead chloride

Question 4

Soluble or insoluble:

Common sulfates

Answer 4

Soluble

EXCEPT: lead, barium and calcium sulfate

Question 5

Soluble or insoluble:

Common carbonates and hydroxides

Answer 5

Insoluble

EXCEPT: any sodium, potassium and ammonium ones

Question 6

In general, what type of reaction do you use to form an insoluble salt?

Answer 6

Precipitation reaction

Combine two soluble salts and react them to precipiate an insoluble salt

Question 7

Give an example of a precipitation reaction (word and chemical equation)

Answer 7

lead nitrate + sodium chloride
—–> lead chloride + sodium nitrate

Pb(NO3)2 (aq) + 2NaCl (aq) —-> PbCl2 (s) + 2NaNO3 (aq)

Question 8

Describe an experiment to produce insoluble lead chloride

Answer 8

1. Add spatuala of lead nitrate to a test tube and dissolve in deionised water
2. Add spatuala of sodium chloride to a test tube and dissolve in deionised water
3. Tip the two solutions into a beaker and stir until fully mixed - the lead chloride will precipitate
4. Fold piece of filter paper into a fllter funnel, and place on a conical flask
5. Pour beaker contents into middle of filter paper
6. Swill out the beaker with more deionised water and tipp into filter paper (to ensure you remove all precipitate from the beaker)
7. Rinse the filter paper contents with deionised water to ensure all soluble sodium nitrate is washed away
8. Scrape lead chloride into fresh filter paper and leave to dry in oven or dessicator