If you have two solutions, one of pH 7 and one of pH 9, but they are not labeled, which indicator would be used to identify the two, methyl orange or phenolphthalein?

The mid-point of the phenolphthalein indicator is about 9 (from 8.3 to 10) and the range for M.O. is 3.1 to 4.4. Can you take it from here?

Yes, based on the pH ranges for the indicators, you can determine which indicator would be suitable for identifying the two solutions.

Since one of the solutions has a pH of 7, it falls within the pH range of methyl orange (3.1 to 4.4). Therefore, methyl orange would be appropriate to use in order to identify this solution.

On the other hand, the second solution has a pH of 9, which falls within the pH range of phenolphthalein (8.3 to 10). Hence, phenolphthalein would be suitable to use for identifying this solution.

Therefore, to distinguish the solutions, you can use methyl orange for the solution with pH 7 and phenolphthalein for the solution with pH 9.