Acids, Bases and Salts Flashcards
Definition of an acid
An acid releases H+ ions in aqueous solution. An acid is a proton donor.
Show dissociation of HCl and H2CO3
HCl (aq) –> H+ (aq) + Cl- (aq)
H2CO3 (aq) –> 2H+ (aq) + CO3 2- (aq)
Define a stong acid
A strong acid is fully dissociated in solution
It is not a reversible reaction
Define a weak acid
A weak acid is partially dissociated in solution.
Many are carboxylic or organic acid.
It is a reversible reaction
Show dissociation of CH3COOH
CH3COOH (aq) –> CH3COO- (aq) + H+ (aq)
reversible reaction
Define a base
Bases are proton acceptors
What are the different types of bases
Metal hydroxides
Metal oxides
Ammonia and organic amino compounds
Example of reaction of bases with acids:
NaOH +HCl
MgO + HCl
NH3 + H+
NaOH +HCl –> NaCl + H2O
MgO +2HCl –> MgCl2 + H2O
NH3 (aq) + H+ (aq)–> NH4+ (aq)
Neutralisation reaction
H+ + OH- –> H2O
Define an alkali
An alkali is a water soluble base that releases OH- ions in water e.g. NaOH, KOH, NH3
What happens when acid dissolves in water
The acid dissociates and the hydrogen ion is accepted by a water molecule so the water molecule is acting as a base.
H+ + H2O –> H3O+
(hydronium ion)
Water soluble metal oxide with water
water soluble metal oxide react with water to form aqueous hydroxides
If added to aqueous acid the hydroxide forms can react further to form water.
Water soluble metal hydroxide with water
Water soluble metal hydroxides dissolve and release hydrated OH- ions in water
NaOH (s) + aqua–> Na+ (aq) + OH- (aq)
Water is aqua because it is acting as a solvent and is not reacting chemically.
Define a salt
Salts are ionic compounds formed when H+ ions are replaced by metal ions or ammonium ions
Reactions of acids
Acid + Metal hydroxide –> Salt + Water
Acid + Metal oxide –> Salt + Water
Acid + Metal carbonate –> salt + CO2 + Water
Acid + Reactive metal –> salt + hydrogen