1. Ch. 15 Titration And pH

2. Ionization of Water _____________________: two water molecules produce a hydronium ion and a hydroxide ion by transfer of a proton. 15-2

3. Ionization of Water In a neutral solution, ________________________. Ionization constant of water = K w K w =  H 3 O +   OH -  = 1.0 x 10 -14 M If the  H 3 O +  = 1.0 x 10 -5 M, the solution is _________. ___________________________, so the hydronium concentration is greater than it would be in a neutral solution. 15-3

4. Example Example: A 1.0 x 10 -4 M solution of HNO 3 has been prepared for a lab. Calculate the  H 3 O +  and  OH -  of this solution. _________________________________  H 3 O +  = 1.0 x 10 -4 M _________________________  OH -  = 1.0 x 10 -14 M = 1.0 x 10 -14 M  H 3 O +  1.0 x 10 -4 M = 1.0 x 10 -10 M 15-4

5. Practice 1) Determine the  H 3 O +  and  OH -  of a solution that is 1.0 x 10 -4 M Ca(OH) 2. 15-5

6. The pH Scale _____: the negative of the common logarithm of the hydronium ion concentration. ________________ = - log (1.0 x 10 -7 M) = 7.0 ___________________________ = - log (1.0 x 10 -7 M) = 7.0 pH + pOH = 14.0 ______________________________________________ 15-6

7. The pH Scale

8. Example Example: What is the pH of a solution if the  H 3 O +  is 3.4 x 10 -5 M? pH = -log  H 3 O +  = - log (3.4 x 10 -5 M) On your calculator, ______________________ Keep in mind, it is the negative of the log, so change the sign on your answer: pH = _________ 15-8

9. Practice 2) What is the pH of a solution if the  H 3 O +  is 2.5 x 10 -2 M? - 15-9

10. pH to  H 3 O +  pH = -log  H 3 O +  log  H 3 O +  = -pH ____________________ Example: What is the  H 3 O + ,  OH -  if the pH is 7.52? Is the solution acidic or basic?  H 3 O +  = 10 -pH = 10 -7.52 ____________________________. = 3.0 x 10 -8  OH -  = 1.0 x 10 -14 M = 1.0 x 10 -14 M = _______________  H 3 O +  3.0 x 10 -8 M pH is greater than 7.0, the solution is __________. 15-10

11. pH to  H 3 O +  3) What is the  H 3 O + ,  OH -  if the pH is 12.0? Is the solution acidic or basic? 15-11

12. Indicators ___________________: compounds whose colors are sensitive to pH. _________________: the pH range over which an indicator ___________. ____________: determines the pH of a solution by measuring the voltage between two electrodes that are placed in the solution. 15-12

13. Indicators 15-13

14. Titration _____________: the controlled addition and measurement of the amount of a solution of___________ ________________ required to react completely with a measured amount of a solution of unknown concentration. ___________________: the point at which the two solutions used in a titration are present in chemically equivalent amounts. ____________: the point in a titration at which an indicator changes color. 15-14

15. Titration 15-15

16. Titration 15-16

17. Titration __________________: the solution that contains the precisely known concentration of a solute. __________________: a highly purified solid compound used to check the concentration of the known solution in a titiration. 15-17

18. Buffers Buffered Solution: resists changes in pH with the addition of an acid or a base.

19. Ch. 15 The End! 15-19