When these two compounds are mixed in a solution, a substitution reaction will take place in which the potassium ion will replace the silver ion and form potassium nitrate and silver sulfide will be formed. Silver sulfide is insoluble in water, so it will form a solid.
Ionic equation:
2Ag₊ + 2NO₃₋ + 2K₊ + S⁻² → Ag₂S + 2KNO₃
