Answer :
When analyzing chemical reactions using the activity series, the key idea is that a more reactive metal can replace a less reactive metal in a compound. Here, I will go through each given reaction and determine whether it can occur based on the provided activity series:
1. Reaction: Pt + FeCl3
- Activity Series Position: Pt (Platinum) is at the bottom of the series, whereas Fe (Iron) is higher up.
- Analysis: Platinum is less reactive than Iron. Hence, Platinum cannot replace Iron in the compound.
- Conclusion: This reaction will not occur.
2. Reaction: Mn + CaO
- Activity Series Position: Mn (Manganese) is less reactive than Ca (Calcium), with Calcium higher in the series.
- Analysis: Manganese cannot replace Calcium because it is less reactive.
- Conclusion: This reaction will not occur.
3. Reaction: Li + ZnCO3
- Activity Series Position: Li (Lithium) is at the very top of the series, while Zn (Zinc) is lower down.
- Analysis: Lithium is more reactive than Zinc and can replace Zinc in the compound.
- Conclusion: This reaction will occur.
4. Reaction: Cu + 2 KNO3
- Activity Series Position: Cu (Copper) is significantly lower than K (Potassium) on the activity series.
- Analysis: Copper is less reactive than Potassium and cannot replace it in the compound.
- Conclusion: This reaction will not occur.
Based on these analyses, only the reaction between Lithium and Zinc Carbonate (Li + ZnCO3) will take place. Therefore, the answer is:
[tex]\[ \boxed{3} \][/tex]
1. Reaction: Pt + FeCl3
- Activity Series Position: Pt (Platinum) is at the bottom of the series, whereas Fe (Iron) is higher up.
- Analysis: Platinum is less reactive than Iron. Hence, Platinum cannot replace Iron in the compound.
- Conclusion: This reaction will not occur.
2. Reaction: Mn + CaO
- Activity Series Position: Mn (Manganese) is less reactive than Ca (Calcium), with Calcium higher in the series.
- Analysis: Manganese cannot replace Calcium because it is less reactive.
- Conclusion: This reaction will not occur.
3. Reaction: Li + ZnCO3
- Activity Series Position: Li (Lithium) is at the very top of the series, while Zn (Zinc) is lower down.
- Analysis: Lithium is more reactive than Zinc and can replace Zinc in the compound.
- Conclusion: This reaction will occur.
4. Reaction: Cu + 2 KNO3
- Activity Series Position: Cu (Copper) is significantly lower than K (Potassium) on the activity series.
- Analysis: Copper is less reactive than Potassium and cannot replace it in the compound.
- Conclusion: This reaction will not occur.
Based on these analyses, only the reaction between Lithium and Zinc Carbonate (Li + ZnCO3) will take place. Therefore, the answer is:
[tex]\[ \boxed{3} \][/tex]