The following simulation will explore the connection between Kw, [H⁺], [OH^-], and pH. Click on the interactive below and follow the instructions.

Click to Run

Source: Ph Scale, University of Colorado-Physics

Directions:

1. Click “Run” simulation.
2. Click “Reset all.”
3. In the upper left hand corner, use the drop down menu to select and change the solution to water.

Questions:

1. Look at the graph of water components to the right. What relationship do you notice between hydronium and hydroxide ion concentration? What is the pH of this substance?

   Interactive popup. Assistance may be required.

   Check Your Answer

   They are equal (10^-7), pH=7.

2. Move the slider on the pH meter to 12. What changes do you see in the hydroxide and hydronium ion concentration?

   Interactive popup. Assistance may be required.

   Check Your Answer

   The hydronium concentration decreased as the hydroxide ion concentration increased.

3. If you move the slider on the pH meter to 2, what will happen to the concentration of the hydroxide ion concentration?

   Interactive popup. Assistance may be required.

   Check Your Answer

   The hydroxide ion concentration will decrease and the hydronium ion will increase.