Q.

Which one of the following reactions does not belong to ''Lassaigne's test''                [2025]
 

1 Na+X→ΔNaX  
2 2CuO+C→Δ2Cu+CO2  
3 Na+C+N→ΔNaCN  
4 2Na+S→ΔNa2S  

Ans.

(2)

2CuO+C→Δ2Cu+CO2

The given reaction is used to detect the presence of carbon in organic compounds. Lassaigne’s test is used to detect nitrogen, sulphur, halogens and phosphorus in organic compounds.