methyl orange: red at pH < 3.1: orange at pH 3.1-4.4: yellow-orange above pH 4.4
litmus: red at pH < 4.5: purple at pH 4.5-8.3: blue above pH 8.3
thymol blue: yellow at pH < 8.0: green at pH 8.0-9.6: blue above pH 9.6
trinitrobenzene: colorless at pH < 12: yellow at pH 12.0-1: orange above pH 14.0
Which of the pH indicators from the list above would be most appropriate for the titration of 0.30 M aqueous acetic acid (Ka = 1.8 × 10-5) with 0.15 M aqueous sodium hydroxide?
◦ methyl orange
◦ litmus
◦ thymol blue
◦ trinitrobenzene
◦ Both thymol blue and litmus can be used.