when a platinum wire dipped into an unknown solution was held over a Bunsen burner flame, an intense purple colour resulted. when 6 drops of 1M AgNO3(aq) in 6MHNO3(aq) was added to this solution, a white-coloured precipitate formed. What is the chemical formula of this unknown?

Answer 1

Probably KCl.
The purple flame is indicative of potassium; however, my experience is it is not an intense purple flame but a light colored violet and somewhat fleeting when it appears. The AgNO3 test is indicative of chloride ion. However, both tests should be confirmed. A single test never does it.