electrolysis practical Flashcards
what is electrolyisis
breakdown of a substance using electricity
what is an electrolyte
a liquid containing free noving ions which is broken down by electricity during electrolyisis
for the electrolyisis of an aquatic qhy is it able to conduct electricity
solution contains ions which are free to move
what are electrodes made from
graphite
when is a metal formed wt the cathode during electrolyiss of an aquatic
when the metal is more reactive than hydrogen
which metals are more reactive than hydrogen
potassium, sodium, calcium, magnesium, aluminium, zinc, iton, tin, lead
which metals are less reactive than hydrogen
copper, soliver, gold
what would be formed at the cathode if the solution contained cooper
copper
what woukd be formed at the cathode if any metal except copper, silver, gold were in the solution
hydrogen
why would a solution containing copper appear to fade in colour during electrolysis
the copper ions which give the solution its colour have moved to the cathode and formed copper metal, there are fewer copper ions in the solution and so the colour will fade
why would solutions containing any metal apart from copper, silver and gold not appear ti fade in colour over time
the metal ions are more reactive than hydrogen and so are not removed from the solution
what will form at the anode if the negative ion is chloride
chlorine
what will form at the anode if the negative ion is bromide
bromine
what will form at the anode if the negative ion is iodide
iodine
what will form at the anode if the negative ion is nitrate
oxygen
what will form at the anode if the negative ion is sulfate
oxygen
when dies oxygen form at the anode during electrolysis of an aq
if the negative ion is not a group 7 halide
if yiu are asked to collect a gas furing electrolyisis why would you not use a test tube
they dont have a scale so they cant be used to measure volume
if you are asked to collect a gas during electrolysis what should you use to collect it
small measuring cylinder
if you are investigating a hypothesis for electrolyiss what are the possible variables IV and CV
the chemicals in the solution, volume of pure water, concentration of the solution, volume of the solution, distance between electrodes, material of electrodes, same depth of electrodes in the solution, constant power supply, amount of time solution is stirred