Salts

Question 1

Carbonates

Answer 1

all insoluble except sodium, potassium and ammonium

Question 2

Chlorides

Answer 2

all soluble except silver and lead

Question 3

Nitrates

Answer 3

all soluble

Question 4

Sulfates

Answer 4

all soluble except calcium, lead and barium

Question 5

What is precipitation used for?

Answer 5

To make insoluble salts

Question 6

What is crystallisation used for?

Answer 6

To make soluble salts

Question 7

What is titration used for?

Answer 7

to make soluble SPA salts

Question 8

What are the reagents for precipitation?

Answer 8

—–nitrate+sodium—–

Question 9

What are the reagents for crystallisation and titration?

Answer 9

—-carbonate/oxide+—-acid

Question 10

Steps for precipitation
(My Fats Will Disappear)

Answer 10

1. Mix solutions of two soluble salts.
2. Filter the mixture. The residue is the insoluble salt.
3. Wash with distilled water
4. Dry the salt with filter paper.

Question 11

Steps for crystallisation (A Fat Hot Cat Will Die)

Answer 11

1. Add excess of the
   carbonate/oxide.
2. Filter mixture to
   remove the excess
   carbonate
3. Heat filtrate to form
   a saturated solution
4. Cool to allow
   crystals to form.
5. Collect the crystals
   by filtration.
6. Wash with distilled
   water and dry crystals with filter paper

Question 12

Steps for titration

Answer 12

Requires the use of pipette & burette to measure volumes required.

1. Pipette 25 ml alkali to conical flask, fill up
   burette with acid (or
   vice versa)
2. Add a suitable indicator
3. Determine volume
   required for
   neutralisation (by
   observing colour of
   indicator)
4. Repeat without
   indicator (it is an
   impurity when collecting salt!)
5. Heat until saturated
   solution obtained
6. Leave it to cool for
   crystals to form
7. Wash with distilled
   water to remove
   impurities
8. Dry with filter paper