The two solutions are
CH3COOH (acetic acid) : it is a weak acid and will dissociate less (as its Ka is very low) .Even then it will give an acidic solution. The concentration of proton will be less but it will be more than the concentration of hydroxide ions and pH of solution will be less than 7.
Thus bromothymol blue will not turn blue
NH3: ammonia
It is a weak base and will dissociate less to give hydroxide ion. EVen then it will be basic in nature. The concentration of hydroxide ion will be less but it will be more than the concentration of protons and pH of solution will be more than 7.
Thus bromothymol blue will turn blue
