Acids & Alkalis Flashcards
Definition of acid
Substance that releases H+ ions in aqueous solution
Strong acid definition
Completely dissociates when dissolved in water
Weak acid definition
Only partially dissociates when dissolved in water, giving an equilibrium mixture
Write an equation for the dissociation of phosphoric acid
H3PO4 —> PO43- + 3H+
Definition of a base
A substance which neutralises acids (accepts proton)
Definition of an alkali
A soluble base that releases OH- ions in aqueous solution
Do (soluble) metal oxides react with water or dissociate to form hydroxide ions?
They react with water forming hydroxide ions
Do hydroxides react with water or dissociate to form hydroxide ions?
They dissociate
Write the equation for sodium oxide reacting with water to produce OH- ions
Na2O (s) + H2O (l) —> 2Na+ (aq) + 2OH- (aq)
Write the equation for sodium hydroxide dissociating to produce OH- ions
NaOH (aq) —> Na+ (aq) + OH- (aq)
Does ammonia react with water or dissociate to produce hydroxide ions?
It reacts with water to form ammonium ions and hydroxide ions
Write the equation for ammonia reacting with water to produce OH- ions
NH3 (aq) + H2O (l) <—> NH4+ (aq) + OH- (aq)
Definition of salt
A chemical compound formed from the reaction of an acid and a base, with all or part of the hydrogen of the acid replaced by a metal or other cation
Acid + base —>
Salt + water
Acid + alkali —>
Salt + water
Acid + carbonate —>
Salt + carbon dioxide + water
Acid + ammonia —>
Ammonium salt
Soluble salts dissolve in water to form _______ ions
Aqueous
How to write an ionic equation
- write full balanced equation with state symbols
- separate anything that is aqueous into its ions
- cancel out anything that appears on both sides of equation
- write remaining ionic equation
How to write an ionic equation for a precipitate reaction
- only product is precipitate
- only reactants are two aqueous ions that make the precipitate
- don’t have to write out ions and cancel out
