C4

what are strong acids

substances that completely ionise in an water or an aqueous solution. all particles dissociate to release H+ ions.

in the same conc. which acid will have. a higher pH

weak acids

what are weak acids

substances that partially ionise in water only some particles dissociate to release H+ ions

as you increase conc what will happen

pH will decrease regardless of acid strength

as you increase pH by 1. what happens to the conc

divides by ten

what does a higher concentration equal to

faster rate of reaction

why are weak acids reversible

the undissociated and dissociated particles reach an equilibrium

acid + metal oxide → ?

salt + water

acid + metal hydroxide → ?

salt + water

acid + metal carbonate → ?

salt + water + carbon dioxide

acid + metal → ?

salt + hydrogen

metal + water → ?

metal hydroxide + hydrogen

what is reactivity indicated by

number of hydrogen bubbles

what is reactivity

how easily an atom loses or gains electrons and forms ions

what does a higher reactivity equal to

a more explosive reaction

what happens if you keep the mass volume surface area the same and uou increase reactivity

the temperature change greatens/increases

what is oxidisation (electrons)

loss of electrons)

what is reduction (electrons)

gain of electrons

how are metals lower than carbon in the reactivity series extracted

carbon reduction (oxygen)

how are metals higher than carbon in the reactivity series extracted

electrolysis

what is electrolysis

the breaking up of metals from their ore to produce the element using electricity

cathode is…

negative electrode

anode is…

positive electrode

what does the movement of ions create

a flow of charge

how do the metals ions become atoms

gain or lose electrons (reduced or oxidised) from the electricity supply at the cathodes

what cant an ionic solid be electrolysed

ions are in fixed position and can’t move

why can molten ionic compounds be electrolysed

because the ions can move freely and conduct electricity

negatives of electrolysis

expensive to melt

expensive to produce a current

what can be added to the molten solution to lower the melting point

cryolite

what is formed at the bottom of the electrolysis tub

a metal layer is formed (liquid form)

if the metal at the cathode is less reactive than hydrogen what will it produce

a solid layer of metal around the cathode

if the metal at the cathode is more reactive than hydrogen what will it produce

hydrogen gas will be produced from H+ ions reacting

if the non metal at the anode is a halogen what will it produce

halide ions will react to produce halogen molecules (Cl2, Br2 etc)

if the non metal at the anode not a halogen what will it produce

oxygen and water from the OH- ions reacting