1. What is the concentration of the solution?

3. What is in the flask?

4. The acid is HCl and an indicator such as phenolphthalein

5. What is in the flask? H+ The H+ ions cause the indicator to be colourless.

6. H+ OH- Titration begins

7. HCl H+ NaOH Titration begins + water NaCl +

8. H+ OH- Titration begins + water

9. H+ OH- Titration continues + water

10. H+ OH- Titration continues + water But there is enough H+ to keep the indicator colourless.

11. H+OH- Just when all the H+ is used up… + water The indicator changes colour.

12. H+OH- Just when all the H+ is used up… + water This is called the ENDPOINT. And no more OH- is added.

13. H+OH-+ water The moles of H+ is equal to the moles of OH- At the ENDPOINT…

14. At the End-Point … and if moles of base = moles of acid If Molarity = moles Volume then (Molarity acid) (Vol acid)=(Molarity base) (Vol base) then moles = (Molarity) (Volume)

16. known volume At endpoint…

17. (Molarity acid) (Vol acid)=(Molarity base) (Vol base)

18. (Molarity acid) (Vol acid)=(Molarity base) (Vol base)