Titration Demo, Curves and Calculations

• Objectives– Today I will be able to:

• Identify the acid, base, conjugate acid and conjugate base in a reaction• Calculate the concentration of an unknown acid by using titration• Analyze a titration curve to determine the equivalence point of the titration

• Informal assessment – monitoring student interactions and questions as they complete the practice

• Formal assessment – analyzing student responses to the calculations and the exit ticket

• Common Core Connection– Build Strong Content Knowledge– Reason abstractly and quantitatively– Use appropriate tools strategically– Attend to precision

Lesson Sequence

• Evaluate: Warm-Up• Elaborate: Conjugate Acid/Base Practice• Explain and Explore: Titration Notes/Demo/

Curve Analysis• Elaborate: Titration Calculations• Evaluate: Exit Ticket

Warm-Up

• Human blood has a pH of 7.3. Calculate the [H3O+]

• What is the pH of a NaOH solution that has a [OH] of 0.025 M?

• Have your homework out on your desk

Objectives

• Today I will be able to:– Identify the acid, base, conjugate acid and

conjugate base in a reaction– Calculate the concentration of an unknown acid

by using titration– Analyze a titration curve to determine the

equivalence point of the titration

Homework

• Wear closed toe shoes Tuesday and Wednesday next week– (May 6,7)

• Finish Titration Calculations

Agenda

• Warm-Up• Conjugate Acid/Base Practice• Titration Notes/Demo/ Curve Analysis• Titration Calculations• Exit Ticket

Conjugate Acid/Base Practice

For the following, predict the products and label the acid, base, conjugate acid and conjugate base.

NH3(aq) + H2O(l)

Titration Notes/Demo/Curves

• Titration is a neutralization reaction– Products are salts and water– Salt produced can be slightly acidic, slightly basic

or neutral (Depends on acid strength)

Goal of Titration

• Procedure use to determine the concentration of an unknown acid or base

• Standard solution – solution with the known concentration

• A solution is titrated until the concentration of acid=base

• This is called the Equivalence Point

• If an acids and bases are transparent, how can we determine when the concentrations are equal?– Use phenolpthalein as an indicator

• Turns fuchsia in a basic solution• Stop titrating when the solution turns light pink

– This is called the endpoint

Watch Mr. Klotz’s Titration Demo

In the perfect world….

• Equivalence point = Endpoint• Our endpoint will be a little beyond the

equivalence point since we have to see the color change

What is happening during the titration?

We can analyze a titration curve. Take out the curve you completed

for HW.

Think about this!

Why is there a drastic change in the pH when 1.0 L of NaOH is titrated?

Why does the pH stay constant before and after that point?

What is the equivalence point ?

Now we can calculate the concentration of an unknown acid

Mr. Klotz will walk you through a guided notes outline to complete the titration

calculation. Problems not completed in class will become your homework.