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Using the activity series provided, which reactants will form products?



$Na > Mg > Al > Mn > Zn > Cr > Fe > Cd > Co > Ni > Sn > Pb > H > Sb > Bi > Cu > Ag$


A$Ag + NaNO _3 \rightarrow$
B$Fe + Al _2 O _3 \rightarrow$
C$Ni + NaCl \rightarrow$
D$Fe + Cu \left( NO _3\right)_2 \rightarrow$

Verified Answer :

  • The activity series ranks metals from most reactive to least reactive, determining if a metal can displace another from its compound.
  • A metal can only displace another if it is positioned higher in the reactivity list.
  • Evaluating the options: \(Ag < Na\), \(Fe < Al\), \(Ni < Na\), and \(Fe > Cu\).
  • The only reactant pair that leads to a reaction is \(Fe + Cu(NO_3)_2 \rightarrow Fe(NO_3)_2 + Cu\).
  • Final Answer: \(\boxed{Fe + Cu(NO_3)_2 \rightarrow}\)

Explanation

  1. Analyzing the Activity Series Principle

The activity series provided is: \[Na > Mg > Al > Mn > Zn > Cr > Fe > Cd > Co > Ni > Sn > Pb > H > Sb > Bi > Cu > Ag.\] A single-replacement reaction of the form \(A + BC \rightarrow AC + B\) occurs if metal \(A\) is higher in the activity series than metal \(B\). If metal \(A\) is lower in the series than metal \(B\), then metal \(A\) cannot displace metal \(B\), and no reaction occurs.

  1. Evaluating Reactant Pairs

We evaluate each given reactant pair against the activity series:

  1. \(Ag + NaNO_3\): Silver (\(Ag\)) is at the bottom of the series, and sodium (\(Na\)) is at the top. Since \(Ag\) is lower than \(Na\), no reaction occurs.
  2. \(Fe + Al_2O_3\): Iron (\(Fe\)) is positioned below aluminum (\(Al\)) in the series. Since \(Fe\) is lower than \(Al\), it cannot displace aluminum. No reaction occurs.
  3. \(Ni + NaCl\): Nickel (\(Ni\)) is below sodium (\(Na\)) in the series. Since \(Ni\) is lower than \(Na\), no reaction occurs.
  4. \(Fe + Cu(NO_3)_2\): Iron (\(Fe\)) is positioned higher in the series than copper (\(Cu\)). Since \(Fe > Cu\), iron can displace copper from its compound, resulting in a reaction: \(Fe + Cu(NO_3)_2 \rightarrow Fe(NO_3)_2 + Cu\).
  1. Conclusion

Based on the activity series, the only pair that results in a chemical reaction is \(Fe + Cu(NO_3)_2\). The final result is the fourth pair.

Examples

The activity series is crucial in metallurgy and electrochemistry. For instance, in the process of extracting metals from ores, engineers use more reactive metals to displace less reactive ones. Similarly, when installing pipes in a building, one must consider the reactivity of different metals to prevent corrosion, as placing two different metals in contact can lead to a spontaneous electrochemical reaction that degrades one of the metals over time. Understanding this series allows us to predict these reactions and choose materials wisely.

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