Acid-Base Tutorial
Tutorial for Experiment: Acids and Bases
EXAMPLE: Add 25.0 mL of the 0.40 M NH3 and 25.0 mL of the 0.20 M NH4Cl to the
beaker and calculate the pH of the solution in the beaker.
- Select "0.40 M Ammoina" from the Weak Acid or Base pop-up menu.
- Enter 25.0 mL in the box to the right of the Weak Acid or Base pop-up menu.
- Select "0.20 M Ammonium Chloride" from the Salt pop-up menu.
- Enter 25.0 mL in the box to the right of the Salt pop-up menu.
- Since "None" was selected in the Strong Acid or Base pop-up menu, enter 0.0 mL in the box to the right of the pop-up menu.
- Click the "pH" button. At the end of the animation the window will have the appearance illustrated here. Try it.
Calculate the pH of the solution.
To check your answer, click the "Help" button and select "weak base + water —› conjugate acid + hydroxide ion" from the Equilibrium Reaction" pop-up menu.
Enter the initial molarities found in the equilibrium table above. Also enter the value of Kb in the box to the right of the K =.
Enter your calculated pH, 9.56, and click the "Enter" button.
Helpful Hints from "Help"
- If the incorrect pH is entered and all of the other entries are correct, then the following message will appear.
- When incorrect initial molarities are entered and the pH is incorrect, then this message will appear.
- If the wrong value of the equilibrium constant is entered, then the message will read.
