Physical Flashcards
Methyl orange
0-3 red
3-6 orange
6-14 yellow
Phenolphthalein
0-10 colourless
10-14 red
Acid def
A substance that dissolved in water to produce hydrogen ions (H+)
Litmus paper
0-4 red
5-8 purple
8-14 blue
Acid + metal
Salt + hydrogen
Acid+ metal carbonate
Salt + CO2 + water
When testing wait till no more bubbles form to show complete neutralisation
Acid + metal oxide
Salt + water
Acid + metal hydroxide
Salt + water
Solubility
Nitrates
All
Solubility
Chlorides
All but silver and lead
Solubility
Sulfates
All but barium, calcium and lead 2
Solubility
Sodium, potassium and ammonium salts
All
Solubility
Sodium, potassium and ammonium carbonates
All
Insoluble base + acid test
- heat acid
- add base a little at a time
- till excess
- filter (to remove access)
- hydrous? Heat till at least 2/3 of the water had left
- leave to crystallise in a warm place
Remove crystals and then dry
Soluble base + acid test
- aqueous solution of alkali into conical flask and add indicator
- add dilute acid until change in colour
- add powdered charcoal and shake to remove colour
- filter to remove charcoal
- obtain crystals from filtrate
Preparation of insoluble salts
Precipitation reactions!
(Insoluble solid made by chemical reaction in an aqueous solution)
- mix 2 aqueous solution
- one of then contains +ve ion other
- ve ion
- filter
- with the filtrate wash with distiller water to remove traces of the solution formed
- leave to dry
Make ammonia
Whenever ammonium salt reacts with an acid
Indicator needed to decide whether or not reaction is complete
- acid alkali titration
Acid- alkali titration
To find given volume of acid required to react exactly with the given volume if alkali
- use pipette add 25cm3 of alkali solution into conical
- add few drops of indicator
- put acid into a burette and note initial reading
- add acid till change in colour
- not how much was added
- repeat without indicator but the exact volume