Chapter 17 videos
Collision Theory
Equilibrium
Equilibrium Expression
Heterogeneous Equilibria
Le Chatelier’s Priniciple
Solubility Equilibria
Bulldog Chemistry
Thursday, March 29, 2012
Tuesday, March 27, 2012
Ch 16 Review Answers #2-13
- Study definitions from homework and notes. amphoteric, buffered solution, Arrhenius acid-base, Bronsted Lowry acid/base, strong acid/base, indicator equivalence point, titrant
- Write the conjugate acid. For all acids, add H and 1 positive charge
a. SO3 2- b. HS- c. F-
HSO3 - H2S HF
3. Write the conjugate base. For all bases, take off 1 H and add 1 negative charge
a. H2SO4 b. H2CO3 c. HC2H3O2
HSO4- HCO3- C2H3O2-
- Write the formula for common strong and weak acids.
Strong H2SO4 HCl HBr HI HClO4 HNO3
Weak: HF, HC2H3O2 Any acid with carbon is a weak acid.
- Explain how to classify a solution as neutral, acidic or basic by its concentration of H+ and OH-.
Acidic [H+] >[OH-]; Basic [OH-] > [H+] ; Neutral [H+] = [OH-];
- Calculate the concentration of H+ or OH- . Hint: Use the equation for Kw.
a. 1.0 x 10-7 M OH- b. 0.1 M H+
Kw = [H+] [OH-] Kw = [H+] [OH-]
1.0 x 10-14 = [H+] [1.0 x 10-7] 1.0 x 10-14 = [H+] [1.0 x 10—1]
[1.0 x 10-7] [1.0 x 10-7] 1.0 x 10+1 1.0 x 10-1
1.0 x 10-7 = [H+] 1.0 x 10-13 = [H+]
- Classify the solutions as acidic or basic. Which solution is more acidic?
a. pH 12.4 b. pH 3.5 c. pH 1.0
basic acidic acidic C is most acidic
- What is a buffered solution? What is present in a buffered solution? Give an example. A buffered solution resists a change in pH when acids or bases are added to the solution. A weak acid and its conjugate base are present in a buffered solution. HC2H3O2 and NaC2H3O2
9. pH + pOH = 14 Use this equation to calculate the following.
a. pOH = 8.90 b. pH = 1.81
14 - 8.90 = 5.10 14 – 1.81 = 12.19
- What products are formed when a strong acid is added to a strong base?
Neutralization reactions produce a salt and water
- What are the 3 ways to measure pH?
Indicators, pH meter, litmus
- A low pH has a ________ concentration of H+.
a. high b. low c. neutral
- Explain the difference between a strong acid and a weak acid in aqueous solution.
A strong acid dissociates (ionizes) completely and a weak acid partially dissociates (ionizes)
Ch 16 Review Answers #14-19
14. What is the [H+] of a solution in which pOH = 7.9?
1st find the pH by subtracting 14 – 7.9 = 6.1; Use the pH as a negative exponent
1.0 x 10-6
15. Which of the following pairs would make a buffer?
a. HCOOH, HCOO¯ or HCOOH, HCOONa The conjugate base can be missing the acidic H and have a negative sign, or the acidic H can be replaced by any cation.
b. H2SO4, SO42¯
c. C2H2O2¯, H+
d. NO3¯, H+
e. Na+, C2H2O2
16. Determine the volume of 0.100 M KOH needed to titrate 50.0 mL of 0.200 M
HNO3.
M1V1 = M2V2 V1 = M2V2 V1 = (50.0 mL)(0.200 M)
M1 0.100 M
V1 = 100. mL
17. What is the conjugate base of a weak acid? the conjugate acid of a weak base?
They are the opposite. A weak acid has a strong conjugate base. A weak base has a strong conjugate acid
18. What is the formula for the kw of a neutral solution?
Kw = [H+] [OH-]
19. Name 2 weak acids.
HF, hydrofluoric acid and HC2H3O2 acetic acid, Any acid with carbon
Ch 16 Review Answers #20-24
20. What is the numerical difference between each number on the pH scale?
Ten times from 4 to 1 is a difference in 103. The exponent is one less than the number of digits
21. Describe how to make a buffered solution.
Place a weak acid and a compound with its strong conjugate base in the solution
22. What happens to the pH in a titration curve?
The pH rises rapidly when the solution nears the equivalence point
23. On the pH scale, what numbers are acidic, basic, and neutral?
7 is neutral less than 7 is acidic greater than 7 is basic
24. Give the characteristics of an acid and a base.
Acid Base
Tastes sour Tastes bitter
Produces H+ in solution Produces OH- in solution
Produces H2 gas with active metals Feels slippery
Turns blue litmus red Turns red litmus blue
Both
If a strong acid or base, it is a good electrolyte.
Sunday, March 25, 2012
Ch 16 YouTube Video Links
Ch 16 YouTube Videos
Intro
Properties of Acids and Bases
16.1
Arrhenius Acids
Bronsted Lowry Acids http://www.youtube.com/watch?v=0O2GeklXloA
Conjugate Acid/Base Pairs
16.2 Strong Acids and Bases
16.3 and 16.4 pH and pOH
16.7 Titration technique
16.8 Buffered Solutions
http://www.youtube.com/watch?v=0qbvdLgBRH0&feature=related
Chemistry Week of March 26-30 Agenda
CHEMISTRY: Mar. 26-30 2012 Name_______________________________
Tentative Schedule www.lundiechem.blogspot.com Date_____________________Pd_________
Write the Question and the Answer to all ELO problems. Show all math work
MON: Ch 16 Review Sheet
Study for Chapter 16 Test
TUES: Chapter 16 Test
Read pages 537-543. Define the 6 blue, bold-faced words on pp. 537-541.
WED: Discuss ELO:
Notes: 17.1 How Chemical Reactions Occur; 17.2 Conditions That Affect Reaction Rates; 17.3 Heterogenous Reactions
Guided Practice: p. 570 #3 4 5 6 7 8
ELO: Define the 9 boldfaced words p543-554
THURS: Chemical Equilibrium video
Notes: 17.4 The Equilibrium Condition; 17.5 Chemical Equilibrium: A Dynamic Condition 17.8 Le Chậtelier's Principle
Guided Practice: p557 Ex. 17.4; p 558 Self-Ö Ex. 17.3; p560 Ex. 17.5; Self-Ö ex. 17.4;
p.561 Ex. 17.6; p.562 Self-Ö 17.5
ELO: p. 571-572 #27, 31, 32, 33, 34, 35.
FRI: Discuss ELO
http://www.chem.iastate.edu/group/Greenbowe/sections/projectfolder/simDownload/index4.html
Class work: Questions from old Zumdahl book p. 542-543 #34, 36, 38, 39
ELO: Ch 17 Review Sheet
SAVE THIS TO ATTACH TO YOUR HOMEWORK ON FRIDAY
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