Basic Concepts
What is electrolysis
The process of using electricity to cause the decomposition of a compound.
Name all of the ions present in a solution of aqueous sodium chloride.
Na+, Cl-, H+, and OH-.
What is produced at the anode in molten sodium chloride electrolysis?
Chlorine Gas (Cl2)
do not accept any ions.
What is the difference between a strong and weak acid?
Strong acids fully dissociate. Weak acids partially dissociate.
accept words to this effect.
Define an electrolyte.
The substance that conducts electricity when in solution or melted. (The compound being electrolysed)
What is produced at the cathode in copper (II) sulfate electrolysis?
Copper metal (Cu)
do not accept Cu2+ or any ion.
What is produced at the cathode in molten lead (II) bromide electrolysis?
Lead metal (Pb)
do not accept any ions
A negative change in enthlapy is indicative of what type of reaction?
exothermic
Name the two types of electrodes (identify each correctly)
Anode (positive)
Cathode (negative)
What gas is produced at the anode in dilute sulfuric acid electrolysis?
Oxygen gas (O2)
do not accept any ions.
Why are inert electrodes used in molten compound electrolysis?
Inert electrodes do not react with the electrolyte or products of electrolysis.
What is a covalent bond?
A bond formed by a shared pair of electrons. Will only involve non-metals.
What happens during oxidation?
Oxidation is the loss of electrons.
Why is hydrogen produced at the cathode in water electrolysis?
Hydrogen ions (H+) gain electrons at the cathode to form hydrogen gas (H2).
Accept balanced half equation:
2H+ + 2e- --> H2
What are electrodes typically made of when electrolysing molten aluminium oxide in the extraction of aluminium.
Graphite (carbon)
Mr Hoes is from this Canadian province.
Ontario
Why can molten ionic compounds conduct electricity?
Their ions are free to move to the electrodes.
Describe the process of electroplating.
Using electrolysis to deposit a thin layer of metal onto the surface of another metal (or conductive material).
Why is hydrogen gas produced at the cathode during electrolysis of molten sodium chloride?
trick question! muahaha
No H+ present in molten NaCl, so sodium metal will form at the cathode.
A process theoretically yields 50g of zinc. The percent yield is 90%. How much Zinc would you actually yield?
50g x 0.90 = 45g