equation Nh4Cl+NaOH=NaCl+H2O+Nh3 is an impossible reaction. why?
Please note that the reaction of ammonium chloride and sodium hydroxide is not an impossible reaction. This reaction is a very common reaction in which NaOH, being the stronger base decomposes NH4Cl to give NaCl, NH3 and H2O.
NH4Cl + NaOH → NaCl + H2O + NH3