chemical changes Flashcards
what is an electrolysis
the splitting up of an ionic compound using electrolysis
what is an electrolyte
a liquid/solution that are able to conduct electricity as they contain ions
what happens in the electrolysis of molten ionic compounds
- molten ionic compounds are always broken up into their elements
- the metal is produced at the cathode
- the nonmetal is produced at the anode
in the electrolysis of molten ionic compounds what must the electrode be made out of and why
the electrodes should be made of an inert material so they don’t react with the electrolyte
why are some metals extracted from their ores using electrolysis?
as the metal is too reactive to be reduced by carbon or if the metal reacts with carbon
in the electrolysis of aqueous solutions, as well as the ions from the compound, what ions are present and why?
OH- and H+ ions because the compound was dissolved in water
in the electrolysis of aqueous solutions what happens at the anode?
oxygen is produced because the hydroxide ions are discharged, unless a halide is present then the halogen will be produced
in the electrolysis of aqueous solutions what happens at the cathode?
hydrogen is produced if the metal is more reactive than hydrogen
why are H+ and OH- ions present?
in the aqueous water molecules break down
explain why an acid can be described as both dilute and strong
- strong because it completely ionises in aqueous solutions
- dilute because there is a small amount of acid per unit volume (as theres a larger volume of solvent)
how does the PH of an acid depend on its strength and concentration
- as the stronger the acid the greater the ionisation so the lower the PH
- the higher the concentration of an acid the more acid in the same volume of solution. so the higher the concentration of acid the lower the PH
