Question

1. If the hydrogen ion concentration of a solution is 10–10M, is the solution acidic, alkaline, or

Answer 1

B A C is correct. the guy who wrote this is incorrect. I got a 33 with his help. Again the correct answers are B, A and C

Have a great day.

Answer 2

1) If the hydrogen ion concentration of a solution is 10–10M, is the solution is definitely  alkaline. The thing I used to determine that fact is basic point  - pH above 7 is always alkaine, and as a proof we can see from the task that the concentration of hydroxyl OH- is pretty higher than hydrogen H+, which is a direct charachteristic of alkain solution.
Here is a tip for you, I bet it will be useful : 
>7 = basic 
<7 = acidic 
7 = neutral

2) The most suitable answer for the second question is the negative logarithm of the hydrogen ion concentration. Pay attention to letters P and H, which pose as little promt as they point on Potential of Hydrogen. And the reason why it is negative is that scale of Ph is positive by default, but due to the fact that ion concentration is always less than 1, and as a result we get the negative logarithm.

3) According to the small table shown in the first question, the answer is [H+] = 1 x 10–11 M which is  pH 11, as I mentioned, since Ph is above 7 it is a basic solution.