Unit 10.2: Electrochemistry
The requirements of the forthcoming e-assessment, which will take place on Wednesday May 18th, 2016, means that the following topics must be covered during Unit 1b:
Periodic Table: metals, non-metals and transition metals
Metals are very useful in our everyday lives.
Aluminium and titanium are useful metals but are expensive to produce.
a) Metals that are more reactive than carbon, such as aluminium, are
Knowledge of the details of industrial methods of electrolysis is not required
b) Copper can be extracted from copper-rich ores by heating the ores in a furnace (smelting). The copper can be purified by electrolysis. The supply of copper-rich ores is limited
c) New ways of extracting copper from low-grade ores are being researched to limit the environmental impact of traditional mining.
Copper can be extracted by phytomining, or by bioleaching.
Candidates should know and understand that:
d) Copper can be obtained from solutions of copper salts by electrolysis or by displacement using scrap iron.
Candidates should know that during electrolysis positive ions move towards the negative electrode. They do not need to describe this in terms of oxidation and reduction, or to understand half equations
e) Aluminium and titanium cannot be extracted from their oxides by reduction with carbon. Current methods of extraction are expensive because:
Candidates do not need to know the details of methods used to extract these metals, but should be able to comment on and evaluate information that is given about the chemical processes that can be used
f) We should recycle metals because extracting them uses limited resources
and is expensive in terms of energy and effects on the environment.