When working in my Lab with p-nitrophenol ,I added some concentrated HCl and heated until it was fully dissolved. Then I cooled it in ice bath and found a white salt like compound which is not probably p-nitrophenol itself. I am totally puzzled about the reaction involved in that condition , what the product really is . Does anyone have any idea about the reaction occurred in that system ?
No reaction has occurred, you have recrystallised p-nitrophenol! The white solid you have recovered is pure p-nitrophenol. P-nitrophenol is surprisingly soluble is hot water (33g/L at 40C) and crystallises out on cooling. There is no reaction that can take place with cHCl.