need chemistry help!

  1. I have a test on Tuesday and we just had this in lecture last Thursday.

    I am confused about finding the pH of something when given H3O or OH values.

    Example: We are given [OH-] = 1.0 x 10*-4
    We are asked to determine if this solution is acidic or basic, and then determine the pH

    I figured out that [H3O+] = 1.0 x 10*-10 . Since there is more H30 than OH then it should be an acidic solution, right?

    But then the pH is 10 and that is a pH that falls under the basic category on the pH scale.

    I am obviously not understanding something here. Can anyone help?
  2. Visit AmericanChai profile page

    About AmericanChai

    Joined: May '06; Posts: 273; Likes: 166


  3. by   leximast1
    You did all the hard work. You just have to look harder at the numbers.
    [OH-] = 1.0 x 10*-4
    [H3O+] = 1.0 x 10*-10
    Which is a larger number? remember what 10-4 & 10-10 means.

    Good luck on you test. I have one on Monday and Final on Wednesday.
  4. by   AmericanChai
    :smackingf Oh now I see! Thanks for replying. Good luck with your exams! My semester will be over on Dec 12th. Yeah!