Paper 1- 3b Electrolysis Flashcards
Oxidation in terms of electrons
oxidation is loss of electrons
Reduction in terms of electrons
reduction is gain of electrons
Define electrolysis
breaking down an ionic substance
using electricity
What is the anode?
the positive electrode
What is the cathode?
the negative electrode
What the ions in NaCl?
Na+ and Cl-
What are the ions in MgO?
Mg2+ O2-
What are the ions when water dissociate?
H+ and OH-
Rule for the negative electrode with a solution?
If metal is more reactive than hydrogen
At the positive electrode….
negative ions
lose electrons
to become atoms
At the negative electrode…
positive ions
gain electrons
to become atoms
Ions made when water dissociates
H+ and OH-
Which ions are in NaCl?
Na + and Cl-
What does dissociate mean?
Splits up
Into it’s ions
(usually when dissolved)
Which ions are in MgO
Mg 2+ and O-
Which ions are in AgCl
Ag+ and Cl-
Which ions are in PbBr2
Pb 2+
and 2 x Br-
Which ions are in aqueous Na Cl
H+, Na+
OH-, Cl-
Rule for the negative electrode
Metal is more reactive than hydrogen = hydrogen formed
Metal is less reactive than hydrogen= hydrogen is formed
Rule for the positive electrode
If Grp 7 ion is present it is formed
/If no Grp 7 ion is present oxygen is formed
What is the half equation for the production of water in aqueous solution?
4OH- –> O2 + 2H2O + 4e-
Ions in hydrochloric acid HCl
H+ and Cl-
Ions in sulphruic acid (H2SO4)
H+ and SO4 2-