Mrs. Cook's Blog

AP Chemistry: Week of March 1

College Board Course Description

III. Reactions

A. Reaction types

1. Acid-base reactions; concepts of Arrhenius, Brønsted-Lowry, and Lewis; coordination complexes; amphoterism

B. Stoichiometry

    1. Ionic and molecular species present in chemical systems: net ionic equations

    3. Mass and volume relations with emphasis on the mole concept, including limiting reactants

C. Equilibrium

1. Concept of dynamic equilibrium, physical and chemical; Le Chatelier’s principle; equilibrium constants

    2. Quantitative treatment

    a. Equilibrium constants for gaseous reactions: Kp, Kc

    b. Equilibrium constants for reactions in solution

    (1) Constants for acids and bases; pK; pH

    (2) Solubility product constants and their application to precipitation and the dissolution of slightly soluble compounds

    (3) Common ion effect; buffers; hydrolysis

 

 

Monday, 3/1:  Continue with lab 15 (Parts 1 & 2)

 

Tuesday, 3/2:  AP problems worksheet due

 

Wednesday, 3/3:  Acid-Base test #2, Homework due, Lab 15 due (Questions 1-5, 7.  No “Sources of Error”)

 

Thursday, 3/4:  Start Atomic Theory Unit. 

College Board Course Description

I I. Structure of Matter

A. Atomic theory and atomic structure

1. Evidence for the atomic theory

4. Electron energy levels: atomic spectra, quantum numbers, atomic orbitals

 

Friday, 3/5: Reactions half-test

Homework: Work samples 6.1, 6.2, 6.3 (start pg 214)  and page 247,  #13, 15, 23, 25, 29

Read about Photoelectric effect (page 216)

 

AP Chemistry: Post lab 17 - changes to questions

Post lab question #4:  Compare 3 and 4

Post lab question # 6: Compare 3 and 6

Post lab question #8: Compare 3 and 8

AP Chemistry: Lab 17 report due date

Changed to Friday, 2/26

Also due on Friday (so don't procrastinate): Prelab 16 = graded homework, and prelab 15

Honors Chemistry: Week of February 22

Chapter 15: Solutions

Unit GPS:  SC7. Students will characterize the properties that describe solutions and the nature of acids and bases.

a. Explain the process of dissolving in terms of solute/solvent interactions:

• Observe factors that effect the rate at which a solute dissolves in a specific solvent,

• Express concentrations as molarities,

• Prepare and properly label solutions of specified molar concentration,

 

Homework of Reaction Stoichiometry (Chapter 9) Test Day – Tuesday, 2/23:  solutions worksheet

 

Wednesday & Thursday, 2/24 & 2/25

definitons (Page 520): solution, solvent, solute, aqueous

mixture: two or more components retain their own characteristics and can be separated by physical means

alloy:  solid-solid solution with metallic properties

 

Recall ion-dipole attraction:  explains how ionic solutes dissolve in water (see Figure 15.1 on page 521)

Recall dipole-dipole attractions.  Page 522.

“Like dissolves like”   It’s not the oil and water repel.  They are attracted (LD forces).  Water attraction for water is stronger. (Figure 15.2 on page 523)

 

Saturated, unsaturated, supersaturated, concentrated, dilute – Page 525

 

Classifying water soluble compounds

strong electrolyte – lots of ions, conducts electricity well (Soluble ionic compounds, strong acids, strong bases)

weak electrolyte – some ions, conducts electricity a little (slightly soluble ionic compounds, weak acids, weak bases)

    nonelectrolyte – no ions, does not conduct electricity (all other covalent compounds)

 

Collligative properties:  Depend only on the number of solute particles present in the solution.  Do not depend on the type of particle.

Freezing point depression and boiling point elevation:  Page 552

 

Moles of ions per mole of solute   Homework: Page 527, #2

 

concentration - amount of solute in a given amount of solvent or solution

 

Molarity = moles solute/liter solution  (M = mol/L)     Page 530

    Solve for other 2 variables.

    Example 15.3 on page 531 and 15.4. Practice 15.4

    Homework, Page 555, #19, 21ab, 22ab

    Example 15.5 on page 533.  Practice 15.5    Homework, Page 556, #25

    Example 15.6 on page 534.  Practice 15.6 

    Example 15.7 on page 535.  Practice 15.7 Homework, Page 556,  #27ab, 30

 

 

Dilution:  Fish tank (10 fish in 5 gal ® 10 fish in 10 gal)

    See page 536 for pictures and blue highlight. M₁V₁ = M₂V₂

Example 15.8 on page 539. Practice 15.8 and Page 540, #7 (answer = 1.17 M NaCl)

 

Homework: Page 555, #31ab, 32 HCl only 

 

 

 

Friday and Monday, 2/26 & 3/1: Solutions lab

  

Tuesday, 3/2: Post lab and check review assignment

 

Wednesday, 3/3: Test Chapter 15

AP Chemistry: Week of February 22

College Board Course Description

III. Reactions

A. Reaction types

1. Acid-base reactions; concepts of Arrhenius, Brønsted-Lowry, and Lewis; coordination complexes; amphoterism

B. Stoichiometry

    1. Ionic and molecular species present in chemical systems: net ionic equations

    3. Mass and volume relations with emphasis on the mole concept, including limiting reactants

C. Equilibrium

1. Concept of dynamic equilibrium, physical and chemical; Le Chatelier’s principle; equilibrium constants

    2. Quantitative treatment

        a. Equilibrium constants for gaseous reactions: Kp, Kc

        b. Equilibrium constants for reactions in solution

        (1) Constants for acids and bases; pK; pH

(2) Solubility product constants and their application to precipitation and the dissolution of slightly soluble compounds

        (3) Common ion effect; buffers; hydrolysis

Monday, 2/22: Page 760, #25, 27, 31 and due on Firday = Lab 17 Report (Identifiers, Title, Purpose, Procedure, Data, Post-lab Calculations and Analysis #1-8, Prelab Questions 3 & 4, Sources of Error: Explain any data that does not follow the expected pattern.)

    Note for questions 1-8:  “Steps” refers to your data table – not to procedural steps.

Tuesday, 2/23: Page 760, #33, 35, 37 and study for tomorrow's Reaction Test.

Wednesday, 2/24:  Page 761, #39ab, 41, 43, 45

    Graded homework: Prelab 16 due Friday, 2/26

Prelab 15 due Friday, 2/26.  AP Worksheet due Tuesday, 3/2.

Thursday, 2/25:  Catch-up or Work day

Friday, 2/26 & Monday, 3/1:  Lab 15 Parts 1 & 2. 

    Part 1:  Start by making 250 mL of 0.1 M NaOH.  Use your own base solution for all titrations.

    Lab Report due Wednesday, 3/3 (Identifiers, Title, Purpose, Procedure, Data including letter of unknown, Post-lab Calculations and Analysis #1-5, 7)

Tuesday, 3/2:  AP Worksheet due.  (Checking to see if you have completed it for 25 participation points)

 

Wednesday, 3/3:  Test Acid-Base #2

AP Chemistry: Acids & Bases - Part Two - notes and assignments

Common ion effect using Le Chatelier. 

    HA ® H+ + A-       MA ® M+ + A- 

    Large [A-] drives [H+] down.

Calculating pH with a common ion. Page 720, Sample 17.1 and Sample 17.2 and one of the practice.problems (Students choose)

Homework:  Page 759, #21

buffer:  Mixture of weak acid and conjugate salt or weak base and conjugate salt. 

Effect = hold pH steady: either the H+ or A- is available for neutralization.

See page 704 pictorials.

Note:  Henderson-Hasselback on page 725.

    Samples 17.3 – 17.2  (Practice problems for both)

    Read 2 paragraphs on page 726-727:  Buffer capacity and pH range.

Note:  flow chart on page 727:  Neutralization First.  Then equilibrium.

    Sample 17.5 on page 728.  Recall: K_aK_b=K_w  

Homework: page 760, #25, 27

How to make a buffer:

    Equal moles weak acid and conjugate base

    Equal moles weak base and conjugate acid

    Weak acid and half # of moles of strong base

    Weak base and half # of moles of strong acid

Homework: page 760, #31

Equivalence point: the point in the titration where an exact amount of base has been added to exactly react with all the acid originally present.

What happens at the equivalence point?  Hydrolysis  Kw = Ka  Kb

    Kb A- + H2O « HA + OH-

    Ka    HB+ + H2O « B + H3O+

Titration Curve - Equivalence point = inflection point = midpoint of steep part of the curve 

Pg 736: The equivalence point is defined by stoichiometry, not by pH.

   

Recall: pKa = pH at 1/2 volume of endpt (ideal buffer  [acid] = [conjugate base])

    Ka = [H+][A-]/[HA]  and [A-] = [HA]

    then Ka = [H+]    and pKa = pH

Indicators – Page 679 

Look at curves in book on pages 731-737

Review:  Polyprotic acids: - more than 1 H+ can be removed

    K1 1st proton off,  K2 2nd proton off,   K = K1K2

    K1 > K2 usually a lot bigger

Homework: Read Section 17.3   Pg 760, #33, 35, 37

Add numbers to the sketches.  Flow Chart

Sample pages 731 to 736

Homework: 

Prelab 16 (Graded homework)

Page 761, #39ab, 41, 43, 45 

Lab 17 parts 1 & 2 Report:  Identifiers, Title, Purpose, Procedure, Data, Post-lab Calculations and Analysis #1-8, Prelab Questions 3 & 4, Sources of Error

    (Note for questions 1-8:  “Steps”  refers to your data table – not to procedural steps.)

Prelab 15

Lab 15 parts 1 & 2 Report: Identifiers, Title, Purpose, Procedure, Data, Post-lab Calculations and Analysis #1-5, 7

AP problem set

AP Chemistry: A note to parents

Dear AP Parents,

Please don’t panic just yet.  You may notice a low grade for the Reactions test.  It is the sum of the only two reaction quizzes we have taken up to this point.  Your student will be taking a reaction quiz every week (usually Wednesday).  The best two quizzes are added together to make one test grade.  This is very difficult and complex material.  That is why we work on it throughout the semester.  You should see the Reactions test grade climb throughout the semester.

Sufficient progress = 40's in February, 60's in March and 70's in April.

Ways to improve:  Flashcards, rework practice problems, use descriptive chemistry web site (See "useful links and favorite web sites" on left side of blog)

– V. Cook

AP Chemistry: February 17

III. Reactions

A. Reaction types

1. Acid-base reactions; concepts of Arrhenius, Brønsted-Lowry, and Lewis; coordination complexes; amphoterism

B. Stoichiometry

1. Ionic and molecular species present in chemical systems: net ionic equations

3. Mass and volume relations with emphasis on the mole concept, including limiting reactants

C. Equilibrium

1. Concept of dynamic equilibrium, physical and chemical; Le Chatelier’s principle; equilibrium constants

2. Quantitative treatment

a. Equilibrium constants for gaseous reactions: Kp, Kc

b. Equilibrium constants for reactions in solution

(1) Constants for acids and bases; pK; pH

(2) Solubility product constants and their application to precipitation and the

dissolution of slightly soluble compounds

(3) Common ion effect; buffers; hydrolysis

Homework: Prelab 17 (Questions 1 &2)

Thursday, 2/18: Lab 17, Parts 1 & 2  (Lab will not be due until later next week.)

Honors Chemistry: Week of February 16

GPS:

SCSh5. Students will demonstrate the computation and estimation skills necessary for analyzing data and developing reasonable scientific explanations.

d. Express appropriate numbers of significant figures for calculated data, using scientific notation where appropriate.

e. Solve scientific problems by substituting quantitative values, using dimensional analysis and/or simple algebraic formulas as appropriate.

SC2 Students will relate how the Law of Conservation of Matter is used to determine chemical composition in compounds and chemical reactions.

d. Identify and solve different types of stoichiometry problems, specifically relating mass to moles and mass to mass.

e. Demonstrate the conceptual principle of limiting reactants.

f. Explain the role of equilibrium in chemical reactions.

 

 

Tuesday, Feb 16: Reaction Stoichiometry Worksheet

Wednesday, Feb 17: Page 312, #30,33,34

Thursday, Feb 18:  “Percent Yield” prelab

Friday, Feb 19:  Percent Yield formal lab report and review assignment (Page 310, #8d, 9d, 10d, 15d, 16d, 17, 35ab, 40, 42, 43, 45)

 

Tuesday, 2/23:  Chapter 9 test

Wednesday, March 17:  Book project due  (See “useful links and favorite web sites” on left side of blog for rubrics, assignment, parent form)

AP Chemistry: February 15 & 16

Monday:  Lab 22 due & test Chapter 20

Tuesday: Test Chapter 20 continued and Test Reactions