Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Calculating theoretical pH of a solution while taking pH of tap water into account

  1. Mar 22, 2010 #1
    Hello, thanks for reading.

    I am solving a lab problem that involves calculating a theoretical pH value, then testing the experimental pH in a lab with tap water that is not the expected pH 7, and comparing the values.

    I am determining the theoretical pH value of a 0.1M concentration of NaNO2.
    Based on my calculations using the Kb value of 1.96*10-11, the result is pH 8.15.

    Then, after completing the test experimentally by creating a 0.1M solution from solid NaNO2 and 0.250L of pH 4.95 tap water, I I recorded an experimental value of pH 6.75.

    How do I take into account the pH of the tap water to calculate the proper "theoretical pH value"?

    Last edited: Mar 22, 2010
  2. jcsd
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Can you offer guidance or do you also need help?
Draft saved Draft deleted