Predicting Products Of Electrolysis Flashcards
why cant a solid ionic compound be electrolyised
because the ions are in fixed positions and cant move
why can molten ionic compounds be electrolysed
because their ions can freely move and therefore conduct electricity
what happens to positive metal ions during electrolysis
they are attracted to the negatively charged cathode and reduced
what happens to the negative ions during electrolysis
they are attracted to the positively charged anode and oxidised
what are the products from potassium chloride at the anode and cathode if they were to be electrolysed
- the product at the cathode would be the potassium
- the product at the anode would be the chlorine gas
what is the half equation for the reduction of potassium during electrolysis
K+ + e- = K
what is the half equation for the oxidisation of chlorine during electrolysis
2Cl- = Cl2 + 2e-
what will also be reduced or oxidised during electrolysis apart from the ionic compound
- the hydrogen ions (H+)
- and hydroxide ions (OH-) from the water
what will be produced if the metal is more reactive than the hydrogen ions when they are both attracted to the cathode
hydrogen gas will be prodcued
what will be produced is the metal is less reactive than the hydrogen ions when they are both attracted to the cathode
a solid layer of the pure metal will be produced
what is produced at the anode if the hydroxide and halide ions are present
- molecules of the halide will be formed in their halogen form
- such as chlorine being oxidised
what is produced at the anode if only hydroxide ions are present and no halide ions are present
oxygen will be formed
how can you predict whether a metal will be more or less reactive than hydrogen
- by looking at the reactivity series
- and paying attention to the atomic radii that the atoms have according to their period
what are the four ions present in potassium chloride solution
K+ Cl- H+ OH-
