Question

What happens when zinc is added to a solution of iron (II) sulfate?

• A. No reaction takes place
• B. Both metals react with each other to form an alloy
• C. Iron displaces zinc and forms iron sulfate
• D. Zinc displaces iron and forms zinc sulfate

Hint:

Always refer to the reactivity series to predict whether a displacement reaction will occur between a metal and a salt solution. A metal higher in the series will displace a metal lower in the series.

Answer 1

The Correct Option is D

Step 1: Recall the reactivity series of metals.
The reactivity series is an arrangement of metals in descending order of their chemical reactivity. A more reactive metal can displace a less reactive metal from its salt solution. A part of the reactivity series is: Potassium (K)>Sodium (Na)>Calcium (Ca)>Magnesium (Mg)>Aluminium (Al)>Carbon (C)>Zinc (Zn)>Iron (Fe)>Tin (Sn)>Lead (Pb)>Hydrogen (H)>Copper (Cu)>Mercury (Hg)>Silver (Ag)>Gold (Au)>Platinum (Pt)
Step 2: Compare the reactivity of zinc and iron.
From the reactivity series, zinc (Zn) is placed above iron (Fe), which indicates that zinc is more reactive than iron.
Step 3: Predict the outcome of the reaction between zinc and iron (II) sulfate solution.
Since zinc is more reactive than iron, it can displace iron from its salt solution (iron (II) sulfate, \(FeSO_4\)). The reaction will be a single displacement reaction where zinc will replace iron, forming zinc sulfate (\(ZnSO_4\)) solution and metallic iron (Fe). The balanced chemical equation for this reaction is: \[ Zn(s) + FeSO_4(aq) \rightarrow ZnSO_4(aq) + Fe(s) \]
Step 4: Analyze the given options.

1. 
   No reaction takes place:
   This is incorrect because zinc is more reactive than iron.
2. 
   Both metals react with each other to form an alloy:
   Alloys are typically formed by melting and mixing metals, not through a displacement reaction in a solution.
3. 
   Iron displaces zinc and forms iron sulfate:
   This is incorrect because a more reactive metal (zinc) displaces a less reactive metal (iron), not the other way around.
4. 
   Zinc displaces iron and forms zinc sulfate:
   This is correct as explained by the reactivity series.

Therefore, when zinc is added to a solution of iron (II) sulfate, zinc displaces iron and forms zinc sulfate.