To determine the correct chemical equation for the reaction between solid zinc and aqueous cobalt chloride, we need to look at the metal activity series. The metal activity series ranks metals by their ability to displace other metals from compounds; a more reactive metal can displace a less reactive metal from its compound.
1. Identify the Metals in the Compounds:
- Zinc ([tex]\( \text{Zn} \)[/tex]) is the metal in the pure solid form.
- Cobalt ([tex]\( \text{Co} \)[/tex]) is the metal in cobalt chloride ([tex]\( \text{CoCl}_2 \)[/tex]).
2. Check the Activity Series:
- Zinc (Zn) is more reactive than cobalt (Co).
- Therefore, zinc can displace cobalt from cobalt chloride in an aqueous solution.
3. Write the Displacement Reaction:
- Zinc will displace cobalt from cobalt chloride:
[tex]\[
\text{Zn} (s) + \text{CoCl}_2 (aq) \rightarrow \text{ZnCl}_2 (aq) + \text{Co} (s)
\][/tex]
4. Verify the Balanced Equation:
- All elements must be balanced on both sides of the equation:
- Zinc (Zn): 1 atom on both sides.
- Cobalt (Co): 1 atom on both sides.
- Chlorine (Cl): 2 atoms on both sides.
5. Conclusion:
- The balanced equation that correctly represents the reaction is:
[tex]\[
\text{Zn} (s) + \text{CoCl}_2 (aq) \rightarrow \text{ZnCl}_2 (aq) + \text{Co} (s)
\][/tex]
Given the possible options:
- A) [tex]\( \text{Zn} (s) + \text{CoCl}_2 (aq) \rightarrow \text{ZnCl}_2 (aq) + \text{Co} (s) \)[/tex]
- B) [tex]\( 2 \text{ZnCl}_2 (aq) + 3 \text{Co} (s) \rightarrow 3 \text{CoCl}_2 (aq) + 2 \text{Zn} (s) \)[/tex]
- C) [tex]\( \text{Zn} (s) + \text{CoCl}_2 (aq) \rightarrow \text{NR} \)[/tex]
- D) [tex]\( 2 \text{Zn} (s) + 3 \text{CoCl}_2 (aq) \rightarrow 2 \text{ZnCl}_2 (aq) + 3 \text{Co} (s) \)[/tex]
The correct choice is:
A) [tex]\( \text{Zn} (s) + \text{CoCl}_2 (aq) \rightarrow \text{ZnCl}_2 (aq) + \text{Co} (s) \)[/tex]
This reflects the correct displacement reaction based on the metal activity series.
