Salts Flashcards
1
Q
What salts are soluble in water?
A
- all sodium, potassium and ammonium salts (remember SPA)
- all nitrates
- all chlorides except silver and lead(ll) chlorides
- all sulfates except barium, calcium and lead (ll) sulfates
2
Q
What salts are insoluble in water?
A
- all carbonates except SPA carbonates
- silver and lead (ll) chloride
- barium, calcium and lead(ll) sulfates
3
Q
What metals are reactive?
A
- potassium
- sodium
- calcium
- magnesium
- aluminium
- zinc
- iron
- tin
- lead
4
Q
what metals are non-reactive?
A
- copper
- mercury
- silver
- platinum/gold
5
Q
How are insoluble salts prepared?
A
- precipitation method
6
Q
how are soluble salts prepared?
A
- if SPA salt, tritration method
- if non SPA salt, reaction of acid with either, insoluble carbonate, insoluble base or reactive metal
7
Q
Why is reacting salt with acid unsuitable for some metals?
A
- metals such as potassium, sodium and calcium react too violently with acids
- metals such as copper and silver do not react with acids
8
Q
What metals can be safely reacted with acids?
A
- zinc
- magnesium
- aluminium
- iron
9
Q
How is a soluble, non SPA salt prepared?
A
- excess of metal, base or carbonate should be added to ensure that acid reacts completely
- the excess base, metal or carbonate can be removed by filtration
- the salt solution is then heated until a saturated solution is formed
- allow saturated solution to cool so that crystals can form
- filter to collect crystal and dry between a few pieces of filter paper
10
Q
How is barium sulfate (insoluble salt) prepared?
A
- add sodium sulfate solution to barium nitrate solution in a breaker
- a white ppt of barium sulfate is formed
- filter to obtain ppt
- wash ppt with some cold, distilled water to remove impurities
- dry ppt of barium sulfate between pieces of filter paper
11
Q
How is potssium sulfate (SPA salt) prepared?
A
- place a known volume of sulfuric acid in a conical flask using a pipette
- add indicator (methyl orange) to acid
- add potassium hydroxide from a burette until indicator changes colour (end of tritration)
- record volume of alkali (potassium hydroxide) used
- repeat with known volumes of acid and alkali to produce salt solution (do not add indicator)
- heat salt solution until saturated solution is formed
- allow saturated solution to cool so crystals can form
- filter to obtain crystals and dry between pieces of filter paper
