Flashcards in Electrolysis Deck (8)
Explain why magnesium chloride must be molten or dissolved in water to be electrolysed. 
- melted / dissolved ions can move...
- ...to the electrodes
- ...and carry charge
Explain how magnesium is produced at the negative electrode. 
- magnesium (ions) get attracted to the electrode
- ...so magnesium ions gain 2 electrons
Why must zinc chloride be molten for electrolysis? 
so ions can move (and carry charge)
Davy first tried to electrolyse a solid potassium salt to produce potassium. Explain why this electrolysis did not work. 
- current / charge couldn’t flow...
- ...because the ions / particles
- (salt) needs to be molten /
dissolved (to conduct electricity)...
- ...so that the ions / particles can
Humphrey Davy’s experiment to produce this new element was quickly accepted by
Suggest why. 
- he had status
- he had evidence / proof
A student dissolved some potassium chloride in water.
The student tried to electrolyse the potassium chloride solution to produce potassium.
The student expected to see potassium metal at the negative electrode, but instead saw bubbles of gas.
- Name the gas produced at the negative electrode.
- Explain why this gas was produced at the negative electrode and why potassium was not produced. 
- hydrogen / H₂
- the ions are positive
- potassium is more reactive (than hydrogen)
- potassium ions are less easily...
- ...discharged / reduced
Potassium metal was produced at the negative electrode.
Describe how potassium atoms are formed from potassium ions. 
- potassium ions gain...
- ...one electron