A student places a clean iron nail in a blue copper sulphate solution. After some time, the solution turns green and a reddish-brown coating appears on the nail. What is the correct conclusion from this experiment?
Answer and explanation
Correct answer: Iron displaces copper from its salt solution, forming iron sulphate.
Iron is more reactive than copper. Therefore, it displaces copper from copper sulphate solution. This is a displacement reaction:
\(\mathrm{Fe + CuSO_4 \rightarrow FeSO_4 + Cu}\)
The iron sulphate formed makes the solution green, while displaced copper deposits as a reddish-brown coating on the nail. Option B is incorrect because copper is less reactive than iron and cannot displace iron.
Frequently asked questions
What is the correct answer to this question?
Iron displaces copper from its salt solution, forming iron sulphate.
Why is this the correct answer?
Iron is more reactive than copper. Therefore, it displaces copper from copper sulphate solution. This is a displacement reaction:
\(\mathrm{Fe + CuSO_4 \rightarrow FeSO_4 + Cu}\)
The iron sulphate formed makes the solution green, while displaced copper deposits as a reddish-brown coating on the nail. Option B is incorrect because copper is less reactive than iron and cannot displace iron.
Which subject and chapter does this question cover?
This is a Class 10 Science question. Chapter: Chemical Substances – Nature and Behaviour. Topic: Chemical Reactions and Equations.
