Acids, Bases and Salt Preparations Flashcards
Sodium compounds
Soluble
Potassium compounds
Soluble
Ammonium compounds
Soluble
Nitrate compounds
Soluble
Common chlorides (not silver and lead(II))
Soluble
Common sulfates (not barium, calcium and lead(II))
Soluble
Common carbonates (not sodium, potassium and ammonium)
Insoluble
Common hydroxides (not sodium, potassium, ammonium and calcium (slightly))
Insoluble
Metal + acid
Salt + hydrogen gas
What observations can be made when a metal reacts with an acid?
- Rapid fizzing
- Colourless gas is evolved (which pops with a lit splint (test for hydrogen))
- Mixture becomes very warm
- Metal gradually disappears to have a colourless solution
Base + acid
Salt + water (most require heating)
Metal carbonate + acid
Salt + carbon dioxide + water
Metal oxides, metal hydroxides and ammonia can…
Act as bases
Alkalis
Soluble bases
Neutralisation
- Measure 50cm3 of dilute acid in a beaker and heat it in a tripod and gauss using a Bunsen burner
- Add excess reactant and heat and stir till no more reacts
- Filter off the excess and transfer the filtrate to an evaporating basin
- Heat the solution to boil off the water
- Allow crystals to form and solution to cool before filtering off the crystals
- Dry off the crystals
Titration
- 25cm3 of metal hydroxide solution is transferred to a conical flask by a pipette and a few drops of methyl orange are added as an indicator
- Dilute acid is added from a burette until the indicator just turns from yellow to orange
- The volume of acid is noted and the same volumes of acid and alkali are mixed together in a clean conical flask without indicator
- The solution is heated to evaporate off the water until it is saturated, then left to cool so crystals form
- Filter off the remaining solution
- Dry off the crystals
Precipitation
- Mix 25cm3 of each reactant
- Filter off the remaining solution
- Wash the residue with distilled water to filter out any contaminants (this needs to be repeated)
- Dry off the salt
If the salt is insoluble
Precipitation
If the salt is sodium, potassium or ammonium salt
Titration
If the salt is soluble but not a sodium, potassium or ammonium salt
Neutralisation