2. Catalyst 1. What is the difference between a strong base and a weak base? 2. What does it mean for something to dissociate? 3. What are the units of Molarity? What does Molarity mean? End

4. Justify – TPS Why did the solution of NaOH change colors the way that it did once I mixed the two?

5. LECTURE 6.4 – ACID/BASE TITRATIONS

6. Today’s Learning Targets 6.6 – I can calculate the concentration of an unknown acidic solution using a titration.

7. Today’s Focus Question I have my acid that I need to dispose of my body with, but how do I know the concentration so as to ensure it is strong enough to dissolve everything?

8. What are indicators?

9. I. Acid/Base Indicators Indicators – Some compounds change color depending on pH. Therefore, these compounds tell us the general pH of our solution based their color

10. How are indicators used in titrations?

11. I. Titrations Often times, we have solutions of unknown concentrations Titration – The controlled addition of solution of known concentration/volume to a solution of known volume, but unknown concentration.

12. Acid/Base of known volume and unknown concentration with an indicator. Acid/Base of known volume and concentration.

14. II. Equivalence Point Equivalence Point – The point at which the two solutions used in a titration are present in equal amounts. We use indicators to spot this point For this class, always at pH = 7 Moles of acid = moles of base at this point

16. How are titrations used to calculate concentrations?

17. I. Calculating Concentration for Titrations Volume of base that was added in titration Molarity of base Volume of unknown acid Mole Ratio from balanced chemical reaction

18. Class Example If it takes 0.540 L of 0.1 M NaOH to neutralize 0.125 L of an HCl solution, what is the concentration of the HCl?

19. Class Example If it takes 0.140 L of 0.051 M HNO 3 to neutralize 0.225 L of an LiOH solution, what is the concentration of the HNO 3 ?

20. Table Talk It takes 2.540 L of 1.1 M HBr to neutralize 1.25 L of an KOH solution, what is the concentration of the HBr?

21. Quiz You have 15 minutes to complete this quiz.

22. Around the World There are 6 questions for you to try around the room.

23. SUMMARIZE

25. Closing Time Worksheet 6.3 is due on Thursday/Friday