pH problems

There was a request for a couple of problems to solve for pH. I put them on blackbaud as an "assessment." If you have trouble with it, let me know. I'm testing out the process.

There were some problems with the program. As an additional place to see the questions, I'll place them here:

  1. True or false: The pH and the pOH are always equal
  2. You have a solution of 0.0125M HCl, which is a strong acid. Calculate the pH of that solution (be careful with sig figs on this). 
  3. You make a solution in which you dissolve 0.20g of NaOH in water to a total volume of 500. mL (3 sig fig). What is the pH?
  4. You mix the 10.0mL of each of HCl and NaOH solutions. What is left in "excess."-(OH- or H+)
  5. What is the final pH of the solution of this mixture?






Answers:
false
1.90
12
H+
2.9
(the previous version was wrong…sorry)