Finding H+ and OH-:
There is a second formula for finding H+ and OH-. If you want to find H+ you have to plug this into your calculator: 2nd, log, -(pH) If you want to find OH- you have to plug this into your calculator: 2nd, log, -(pOH) Example question : pH = 4 Find H+! In order to find the answer to the question, you must find it on a calculator. These are the steps: Step 1. Press the 2nd button that may be blue or yellow on the upper left hand corner of your calculator. Step 2. Press log. (The number 10 should appear on your screen) Step 3. Press the negative button on the lower right hand side of your calculator. Step 4. Plug in the pH (which in this case would be 4) Step 5. Press enter. This is what you should see on your calculator: 10⁻⁴ = 1E -41E -4 can also be written in scientific notation as: 1 × 10⁻⁴ If these directions were not helpful, watch this video: |
Before you take the test, lets review the formulas:
- pH: pH = -log [H+]
- H+: 2nd Fn log [ -pH] = [H+]
- pOH: pOH = -log [OH-]
- OH-: 2nd Fn log [ -pOH] = [OH-]
- pH or pOH: pH + pOH = 14
- H+ or OH-: [H+][OH-] = 1E-14 (written in scientific notation as: 1x10-14)
Feel like you understand everything? Take the quiz!