Download presentation

Published byNora Stephans Modified over 2 years ago

1
Bell Ringer Which of the following aqueous solutions will cause litmus paper to turn red? A NaOH B NaCl C HCl D H2O pH 1-6 7 8-14 Solution Added Acid Neutral Base Litmus paper changes from Blue to Red Does not Change Red to Blue Source: 2003 VA EOC Exam

2
pH Acids and Bases

3
**A Quick Reminder… Reactions can stop at an EQUILIBRIUM NO2 + NO2 N2O4**

Image source:

4
**The Equilibrium Constant, Keq**

For the reaction: aA bB cC + dD Where: a, b, c, d are coefficients A, B, C, D are substances (products) [C]c [D]d Keq = [A]a [B]b (reactants) [ ] = concentration in M

5
**The Equilibrium Constant, Keq**

For the reaction: NO2 + NO N2O4 [N2O4]1 [N2O4] Keq = = [NO2]1 [NO2]1 [NO2]2 2 NO N2O4 [N2O4]1 [N2O4] Keq = = [NO2]2 [NO2]2

6
**A Special Equilibrium Constant, Kw**

For the reaction: H2O H2O H3O OH- [H3O+] [OH-] [H3O+] [OH-] = Kw = [H2O]2 “hydronium” “hydroxide” [1.00 x 10-7] [1.00 x 10-7] = 1.00 x 10-14 Kw = Image source:

7
Practice Problems Using the knowledge that Kw = 1.00 x 10-14, solve for the missing piece of information: 1. Calculate the hydroxide ion concentration in a solution whose hydronium ion concentration is 1 x 10-5 M Kw = [H3O+] [OH-] 1.00 x = [1 x 10-5 M] [OH-] [OH-] = x 10-14 = 1 x 10-9 M 1 x 10-5 M

8
**Practice Problems Kw = [H3O+] [OH-] 1.00 x 10-14 = [H3O+] [0.0010 M]**

2. Calculate the hydronium concentration for a solution whose hydroxide concentration is M. Kw = [H3O+] [OH-] 1.00 x = [H3O+] [ M] [H3O+] = x 10-14 = 1 x M M

9
Practice Problems 3. What is the hydroxide concentration of a solution if grams of NaOH are dissolved in 2.0 L of solution? What is the hydronium ion concentration of this solution? M OH- 1.0 x M H3O+ 1 mol NaOH 1 mol OH- 0.080 g NaOH mol OH- x x = 40.00 g NaOH 1 mol NaOH [OH-] = mol OH- = M OH- 2.0 L Kw = [H3O+] [OH-] 1.00 x = [H3O+] [ M] [H3O+] = x 10-14 = 1.0 x M H3O+ M

10
Practice Problems 4. What is the hydroxide ion concentration of a solution if grams of Ca(OH)2 are dissolved in 2.0 L of solution? What is the hydronium ion concentration of this solution? M OH- 9.3 x M H3O+ 1 mol Ca(OH)2 2 mol OH- 0.080 g Ca(OH)2 mol OH- x x = 74.10 g Ca(OH)2 1 mol Ca(OH)2 [OH-] = mol OH- = M OH- 2.0 L Kw = [H3O+] [OH-] 1.00 x = [H3O+] [ M] [H3O+] = x 10-14 = 9.3 x M H3O+ M

11
**pH – the POWER of H+! pH = the negative logarithm of [H3O+]**

These numbers represent the POWER of H+ pH = the negative logarithm of [H3O+] Image source:

12
**Log-o-rhythms Logarithm Exponent POWER = = pH – the POWER of H+!**

pH = the negative logarithm of [H3O+] POWER pH = - log [H3O+] Answer the following questions without using a calculator: What is the pH of a solution with [H3O+] = 1.0 x 10-4 M? pH = 4.00 ACID What is the pH of a solution with [H3O+] = 1.0 x M? pH = 12.00 BASE

13
**My Kingdom for a Calculator!**

To solve for pH, given hydronium molarity On TI-83: push “(-)” key push “log” key type in number On Scientific Calculators: type in number push “log” key push +/- key

14
**Practice Problems pH = - log [H3O+] pH = - log (1.0 x 10-2) pH = 2.00**

1. What is the pH of a solution if the concentration of hydronium ions is 1.0 x 10-2 M? Is the solution acidic or basic? pH = - log [H3O+] pH = - log (1.0 x 10-2) pH = ACIDIC SIG FIG RULES: Put the correct number of Sig Figs BEHIND the decimal point.

15
**Practice Problems pH = - log [H3O+] pH = - log (1.0 x 10-10)**

2. What is the pH of a solution if the concentration of hydroxide ions is 1.0 x 10-4 M? Is the solution acidic or basic? Kw = [H3O+] [OH-] 1.00 x = [H3O+] [1.0 x 10-4 M] [H3O+] = x 10-14 = 1 x M 1.0 x 10-4 M pH = - log [H3O+] pH = - log (1.0 x 10-10) pH = BASIC

16
**My Kingdom for a Calculator (again)!**

To solve for hydronium molarity, given pH On TI-83: push “10x” key push “(-)” key type in pH On Scientific Calculators: type in number push +/- key push “2nd” key push “log” key

17
**Practice Problems pH = 8.00 = - log [H3O+] -8.00 = log [H3O+]**

3. What is the concentration of hydronium ions in a solution whose pH is 8.00? pH = = - log [H3O+] = log [H3O+] 10–8.00 M = [H3O+] [H3O+] = x 10-8 M

18
**Practice Problems Kw = [H3O+] [OH-]**

4. For Question #3, what is the concentration of hydroxide ions? Kw = [H3O+] [OH-] 1.00 x = [1.0 x 10-8 M] [OH-] [OH-] = x 10-14 = 1 x 10-6 M 1.0 x 10-8 M

19
**Practice Problems pH = - log [H3O+] pH = - log (0.0584) pH = 1.234**

5. What is the concentration of hydronium ions in a solution that has a volume of 2.50 L and 5.33 g of HCl? What is the pH of this solution? 1 mol HCl 1 mol H+ 5.33 g HCl 0.146 mol H+ x x = 36.46 g HCl 1 mol HCl [H+] = 0.146 mol H+ = M H+ 2.50 L pH = - log [H3O+] pH = - log (0.0584) pH =

20
Homework Complete the practice problems on the worksheet. Due next class

Similar presentations

OK

- pH and pOH 1. pH scale developed by a Danish chemist Sören Sörenson Numerical value without units, that communicates the hydrogen ion concentration.

- pH and pOH 1. pH scale developed by a Danish chemist Sören Sörenson Numerical value without units, that communicates the hydrogen ion concentration.

© 2017 SlidePlayer.com Inc.

All rights reserved.

Ads by Google

Ppt on council of ministers of india Ppt on earthquakes and tsunamis How to share ppt on google drive Ppt on branches of chemistry Ppt on steve jobs Free ppt on science and technology A ppt on artificial intelligence Hindi ppt on stress management Ppt on rational numbers for class 10 Ppt on hydrogen fuel cell vehicles