Acids and Bases Flashcards
Formula of compounds formed when sulfur acid reacts with ammonia
what happens?
(NH4)2SO4
ammonia (NH3) becomes ammonium (NH4)
the dissociation of ethanoic acid?
CH3COOH (aq) ⇌ CH3COO-(aq) + H+(aq)
Reversible reaction***
Why is universal indicator not suitable for titration
Too many colour changes
A word equation to show ammonia behaving as a base:
Ammonia + Acid —> Ammonium salt
One product, no water, ammonIUM made
What type of base is Ammonia
Alkaline gas
Ammonia dissociation in water
NH3 (g) + H2O (l) ⇌ NH4+ (aq) + OH- (aq)
reversible
How are soluble and insoluble salts made
Soluble:
1. Titration method (Group 1 Alkalis)
2. Excess solid method (Transition Metals)
Insoluble:
1. Precipitation method
Titration method to obtain crystals
1st time with indicator
2nd time without indicator
Evaporate until point of crystallisation (to remove water)
Cool to crystallise
Filter to obtain crystals
Wash crystals with minimal amounts of cold distilled water
Dry crystals in desiccator
Excess solid method
Solid added to acid until no more reacts so its in excess
Filter to remove excess solid
Wash residue (solid) with water to make sure all of the salt solution is collected
Evaporate to point of crystallisation (to remove water)
Cool to crystalise
Filter to obtain crystals formed
Wash crystals with minimal amounts of cold distilled water
Dry crystals in desiccator
Precipitation method
(if not aqueous): Pour slight excess of water to two soluble solids, stir to dissolve to obtain two solutions
Mix two solutions and stir together
Filter to obtain precipitate
Wash precipitate using distilled water
Dry the precipiate in a desiccator
Hydrated substance def
A substance that is chemically combined with water
Anhydrous substance def
A substance containing no water
Water of crystallisation
The water molecules present in hydrated crystals
