cap 3 - aqueous environments Flashcards
acids
substances that ionise to release H+ ions when dissolved in water
bases
substances that produce OH- ions in solutions
properties of acids:
pH, solutions, taste, feel
pH < 7, forms H+ ions, sour, stinging/burning skins
properties of bases:
pH, solutions, taste, feel
pH > 7, forms OH- ions, bitter, slippery feel
indicators
chemicals that change colour in the presence of an acid and alkali
indicating acids
blue litmus paper becomes red, OR
red/orange with universal indicator
indicating bases
red litmus paper becomes blue, OR
blue/purple with universal indicator
ionisation
where a covalent molecule splits into ions (i.e. all acids)
dissociation
where an ionic compound dissolves in water
strong vs weak
strong: completely ionise/dissociate in water
weak: only partially ionise/dissociate
HCl
strong acid
HNO3
strong acid
H2SO4
strong acid
CH3COOH
weak acid
H3PO4
weak acid
H2CO3
weak acid
common strong bases
group 1 and 2 oxides and hydroxides
NH3
weak base
Na2CO3
weak base
NaHCO3
weak base
concentrated
high molarity
diluted
low molarity
diprotic acids
acids that have two H+ in the structure and release both in solution e.g. H2SO4
(strongly lose first, weakly lose second)
pH scale
inverse logarithmic measure of hydrogen ion concentration
acid + metal
salt + hydrogen gas
acid + metal oxide
salt + water
acid + metal hydroxide
salt + water
acid + metal carbonate
salt + water + carbon dioxide
acid + metal hydrogencarbonate
salt + water + carbon dioxide
base + ammonium salt
salt + water + ammonia (pungent gas)
base + nonmetal oxide
salt + water
self-ionisation (autoionisation) of water
equilibrium reactions that water undergoes on its own, by ionising and recombining constantly
ionic product of water (Kw)
equillibrium constant for the self-ionisation of water
neutrality when
concentration of hydrogen = hydroxide
