Acid Base Titration Curves

What is the equivalence point for a Strong Acid and Strong Base titration?

Thhe Veq for a Strong Acid and Strong Base titration is 7

Describe what the curve for a strong acid and strong base titration will look like

1. Initially, the pH is very low.

2. As the strong base is added, the curve will slowly start to rise

3. Then eventually shoot up

4. It then starts to plateau when excess of the strong base is a added

5. THE Equivalence point is at 7

Describe the curve for a Strong base and Strong acid titration

1. Initially, the pH will be very high

2. Then as more acid is added the pH will decrease slowly and then instantly drop

3. A plateau at a low pH represent the excess acid added

What is the label of the y and x

1. The y axis is the pH

2. The x axis is the volume

What is the equivalence point for a Weak acid and Strong Base Titration?

Think about which one is stronger!

The equivalence point will be just above 7 because we are dealing with a stronger acid.

What will the diagram for a weak acid and strong base titration look like?

1. We start at a relatively higher pH

2. Then there’s a gradual increase as the strong base is added on

3. There wont be a sharp straight line going up like a strong acid, strong base titration but it will go up

4. Then plateau at a high pH

In a Weak Acid- Strong base titration.

How can we work out the pKa?

To get the pKa value, we look at ½ of the equivalence point. This will give us the pH that will then correspond to the pKa value we are looking for.

Repeat but what does the ½ equivalence point on a diagram tell us ?

It tells us about the pKa value

So if the at ½ equivalence point the pH is 4 then the pKa is 4

Where will the pH be for a weak base- strong acid titration?

The pH will be less than 7

What region is considered the Buffer region in a Weak base and Strong Acid titration?

The initial part of the curve to just before the equivalence point

The next 5 takes will consist of questions all in the same group

Review on notebook

50 mL of a 1M HCl solution is titrated with a 0.50M NaOH solution.

Part 1: Calculate the volume of the NaOH solution needed to reach equivalence point

0.1 L or 100 mL

Part 2: What is the pH of the HCl solution before any NaOh is added?

The pH = 0

Part 3: What is the pH of the solution after 30 mL of NaOH has been added?

Strategy used here?

Strategy here is to use ICF table

Answer: 0.359

Part 4: What is the pH of the equivalence point ?

Strong base, Strong Acid titration and so the equivalence point will just be 7

Part 5: What is the pH of the solution after 125 mL of NaOH has been added?

The pH = 12.85