Why does a green solution form when an iron nail is placed in copper sulphate solution?
Answer and explanation
Correct answer: Iron(II) sulphate is formed
Iron is more reactive than copper, so it displaces copper from copper sulphate solution: Fe + CuSO₄ → FeSO₄ + Cu. The deposited copper appears reddish brown, while aqueous iron(II) sulphate is pale green, causing the solution to become greenish. Sodium chloride, barium sulphate, and magnesium oxide contain elements not involved in this reaction, so they cannot explain the observation.
Frequently asked questions
What is the correct answer to this question?
Iron(II) sulphate is formed
Why is this the correct answer?
Iron is more reactive than copper, so it displaces copper from copper sulphate solution: Fe + CuSO₄ → FeSO₄ + Cu. The deposited copper appears reddish brown, while aqueous iron(II) sulphate is pale green, causing the solution to become greenish. Sodium chloride, barium sulphate, and magnesium oxide contain elements not involved in this reaction, so they cannot explain the observation.
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.
