We are asked to give an indicator that could narrow the pH range of the solution.
Recall that indicators are substances that changes color due to pH
• An indicator with a pH range of 3.2 to 4.4
• In an acidic solution, it gives a red colored solution while in a basic solution it is colored yellow
Addition of the indicator methyl orange to an unknown solution leads to a yellow color. The addition of bromthymol blue to the same solution also leads to a yellow color.
Is there another indicator you could use to narrow the range of possible pH values for the solution?