the colour of the solution observed after about 1 hour of placing iron nail in copper sulphate solution is
What is the color change observed when an iron nail is placed in copper sulfate solution after about 1 hour?
Answer: When you place an iron nail in a copper sulfate (\text{CuSO}_4) solution, a chemical reaction takes place. Originally, copper sulfate solution is blue in color due to the presence of \text{Cu}^{2+} ions. As the reaction progresses, the iron displaces the copper ions in the solution:
\text{Fe(s)} + \text{CuSO}_4(\text{aq}) \rightarrow \text{FeSO}_4(\text{aq}) + \text{Cu(s)}
In this reaction, solid iron (Fe) displaces copper (Cu), forming iron(II) sulfate (\text{FeSO}_4) in the solution, and copper is deposited as a reddish-brown solid on the iron nail.
After about 1 hour, the solution observed turns greenish or light green. This color change occurs because the initial blue \text{Cu}^{2+} ions are replaced by the newly formed \text{Fe}^{2+} ions, and iron(II) sulfate solution tends to have this greenish coloration. This is a classic example of a single displacement reaction in chemistry.
By observing these changes, students can get hands-on experience with redox reactions and the concepts of displacement series. Keep in mind that the exact color observed may vary slightly depending on concentration, light, and other laboratory conditions. @username