Question
4 An iron nail and a copper coin are placed in separate solutions of copper(II) sulfate. The nail and the coin are removed from the copper(II) sulfate solutions after one hour. Table 2 shows the recorded observations. object & observations iron nail & brown coating, solution loses blue colour copper coin & no coating, solution remains blue Table 2 Explain, in terms of oxidation and reduction, the observations shown in Table 2. You may include equations to support your answer.
Answer
3.2
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Stuart
Professional · Tutor for 6 years
Answer
Within the solution having the iron nail, the iron gets oxidized by gaining electrons to emerge as Fe(^2+) and copper from CuSO
gets reduced when converted to solid copper that coats the iron nail. Consequently, the solution's blue color declines, suggesting reduced copper ions in solution. Concerning the copper coin immersed in CuSO
, copper isn't strong enough a reductant to incur any reaction. Hence, no alternations in the appearance of the coin or color of the solution materializes, signifying neither oxidation nor reduction has actually happened.
Explanation
## Step1: The reactions occurring in both scenarios need to be first understood. The fixation of a brown hue on the nail indicates copper plating, generated by a displacement reaction in which iron displaces copper in copper sulfate(CuSO
) solution. The chemical equation underlying this reaction is: ### **\(Fe (s) + CuSO_{4} (aq) → FeSO_{4} (aq) + Cu (s)\)**In this reaction, iron dissolves into the solution, the sulfate ion remaining passive because Fe
(aq) substitutes for Cu
(aq), projecting movement of electrons from iron to copper. Therefore, the iron undergoes oxidation and copper undergoes reduction.## Step2:Copper coin remaining undisturbed is due to absence of a stronger metal that can displace copper from the copper sulfate(CuSO
) solution. And, CuSO
cannot act upon copper to cause any reaction.### **No reaction: \(Cu (s) + CuSO_{4} (aq) → no reaction\)** So, no perceptible change occurs to the copper coin or the blue colour of the solution. Evidently, no oxidation or reduction transpires.