C4: Quiz 8 – Answers
2)
a) The two ways are:
- Using carbon or reduction with carbon
- Electrolysis
c) Electrolysis is the more expensive process
3) Gain, loss
With respect to oxygen, oxidation is the GAIN of oxygen and reduction is the LOSS of oxygen
4)
a) Zinc has been reduced as it has lost oxygen
b) Carbon has been oxidised as it has gained oxygen
5)
a) 2 Fe2O3 + 3 C –> 4 Fe + 3 CO2
b) Iron has been reduced as it has lost oxygen
c) Carbon has been oxidised as it has gained oxygen
6)
a) 2 CuO + C –> 2 Cu + CO2
b) Copper has been reduced as it has lost oxygen
7) Calcium is more reactive than carbon, which means that carbon cannot displace the calcium in calcium oxide. Therefore, calcium cannot be extracted from calcium oxide by reduction using carbon
1) What is an ore?
2) The reactivity series is given below.
b) How can we extract metals that are more reactive than carbon from their ores?
c) Which is the more expensive process out of reduction with carbon and electrolysis?
3) Fill in the blanks below with the words “gain” and “loss”
With respect to oxygen, oxidation is the ______ of oxygen and reduction is the ______ of oxygen
4) The reaction between zinc oxide and carbon is shown below.
a) Which substance has been reduced? Explain your answer.
b) Which substance has been oxidised? Explain your answer.
5) Iron can be extracted from iron (III) oxide by using carbon to produce pure iron and carbon dioxide. Iron (III) oxide is Fe2O3.
a) Write the balanced chemical equation for this reaction.
b) Which substance has been reduced? Explain your answer.
c) Which substance has been oxidised? Explain your answer.
6) Copper can be extracted from copper oxide (CuO) to produce pure copper and carbon dioxide.
a) Write the balanced chemical equation for this reaction.
b) Which substance has been reduced? Explain your answer.
7) Why can’t calcium be extracted from calcium oxide by reduction using carbon?