Carbon reduces copper oxide to copper. What is oxidised?
- The carbon
- The copper
- The oxygen
Which metal can be extracted by heating its oxide with carbon?
Getting a metal from its oxide is always a reduction.
Circle one: True False
In the reaction of iron oxide with carbon, how do you spot what is reduced?
- Find what burns brightest
- Find what loses oxygen: the iron compound
- Find what is heaviest
Why must aluminium be extracted by electrolysis?
- It sits above carbon in the reactivity series
- It melts too easily
- Carbon is too expensive
Zinc sits below carbon and aluminium sits above. Which claim follows?
- Both need electrolysis
- Carbon extracts zinc but not aluminium
- Carbon extracts aluminium but not zinc
Mia says carbon frees aluminium because carbon burns very hot. What is wrong with her reason?
- Heat never matters in chemistry
- Position in the reactivity series decides, not how hot carbon burns
- Aluminium is not a metal
Iron tools were common while aluminium stayed precious. What best explains the price gap?
- Iron ore sits nearer the surface everywhere
- Aluminium tools break faster
- Iron yields to cheap carbon reduction while aluminium needs costly electricity