Question

Which statement correctly describes a solution with a pH of 9?

1. It has higher concentration of H3O+ than OH- and causes litmus to turn blue.
2. It has a higher concentration of OH- than H3O+ and causes litmus to turn blue.
3. It has a higher concentration of H3O+ than OH- and causes methyl orange to turn yellow.
4. It has a higher concentration of OH- than H3O+ and causes methyl orange to turn red.

Answer 1

Neutral pH is 7, so a solution with a pH of 9 is slightly alkaline. This means it has a higher concentration of OH- than H3O+. Litmus turns from red to blue in alkaline solution, while methyl orange turns from red to yellow. Therefore the only correct answer is 2.
Hope this helps!