The compound originally contained KNO₃ solution.
Step-by-step explanation:
When a mixture which contains either Pb(NO₃)₂ or KNO₃ is added with NaCl solution, no reaction takes place. This confirms the presence of KNO₃ in the solution.
The reason behind the above activity can be attributed to the lower placement of Na (sodium) in reactivity charge than potassium (K). Hence, it cannot displace Potassium (K) from the aqueous KNO₃ solution. Whereas the NaCl reacts with Pb(NO₃)₂ to produce white insoluble precipitate of PbCl₂. This confirms the presence of KNO₃ in solution.