In a simple displacement reaction between copper sulphate solution and iron metal, the reaction produces iron sulphate and which other substance as the displaced metal?

Introduction / Context:
This question explores a classic example of a single displacement reaction in inorganic chemistry. When a more reactive metal is placed in a solution of a less reactive metal salt, the more reactive metal displaces the less reactive one from the solution. The reaction between iron metal and copper sulphate solution is a standard laboratory demonstration of this concept. Understanding which substance is formed alongside iron sulphate helps students visualize how metal reactivity and ionic exchange work in aqueous solutions.

Given Data / Assumptions:
- The reactants are copper sulphate solution and metallic iron.
- The reaction is stated to produce iron sulphate as one of the products.
- You must determine the other substance produced, which is the displaced metal from copper sulphate.
- Options include vinegar, ash, baking soda, and copper.

Concept / Approach:
The key concept is the reactivity series of metals. Iron is more reactive than copper, so when iron metal is placed in copper sulphate solution, iron goes into solution as iron ions and copper is displaced as a solid metal. The balanced reaction can be written as Fe plus CuSO4 gives FeSO4 plus Cu. This shows that iron sulphate and copper metal are formed. Vinegar, ash, and baking soda are not metals and do not appear in the reaction between copper sulphate and iron. Therefore, by understanding displacement reactions and the reactivity series, you can identify copper as the correct displaced substance.

Step-by-Step Solution:
Step 1: Recall the general form of a displacement reaction where a more reactive metal displaces a less reactive metal from its salt solution. Step 2: Write the word equation for the given reaction: iron plus copper sulphate gives iron sulphate plus copper. Step 3: Recognize that in ionic form, Fe atoms lose electrons and become Fe2 plus ions, while Cu2 plus ions gain electrons and become copper metal. Step 4: Identify the products from the reaction equation as iron sulphate in solution and copper metal precipitating out. Step 5: Conclude that the substance forming alongside iron sulphate is copper, so Copper is the correct answer.

Verification / Alternative check:
You can verify this by performing or observing the experiment in a laboratory. When an iron nail is placed in blue copper sulphate solution, the blue color gradually fades as copper ions leave the solution and a reddish brown deposit of copper forms on the nail. The solution turns greenish due to the formation of iron sulphate. This visible change confirms that copper sulphate and iron react to produce iron sulphate and metallic copper. Textbook examples and reactivity series charts support this interpretation.

Why Other Options Are Wrong:
Vinegar is a solution of acetic acid and is not involved in a displacement reaction between copper sulphate and iron. Ash is a residue of combustion, not a metal produced in this reaction. Baking soda is sodium bicarbonate and does not appear in the reaction equation for iron and copper sulphate. None of these substances relate to the exchange of metal ions in this system. Only copper, the metal originally present as Cu2 plus ions in the copper sulphate solution, is displaced to form a solid metal product.

Common Pitfalls:
A common mistake is to look for a product that sounds chemical without checking the reaction pattern, which might lead some students to choose baking soda because it seems like a laboratory substance. Others may simply not recall the reactivity series and guess incorrectly. To avoid such errors, remember that displacement reactions involve swapping of metals between compounds and that iron is more reactive than copper. Therefore, copper is pushed out of solution and appears as a metal, while iron enters the solution as part of iron sulphate.

Final Answer:
The reaction of copper sulphate and iron produces iron sulphate and Copper as the displaced metal.