Mrs. Cook's Blog

Honors Chemistry: Week of November 30

ELECTROCHEMISTRY notes and assignments

This week's lessons are honors material beyond the GPS.

11/30/09 (Monday)

Essential Question: What is redox?

Classwork: Video “The Busy Electron”  (World of Chemistry) Worksheet

12/1/09 (Tuesday)

Essential Question: What is an oxidation number?

oxidation number: Read page 637. Section 18.1 B through first paragraph on top of page 638.

Rules on page 639.

Examples on page 639, 640.  Practice problems on page 640.

Homework: Page 641,  #3, 4 and  Page  662, #7-11

12/2/09 (Wednesday)

Essential Question: What is oxidation-reduction (redox)?

oxidation - lose electrons; reduction - gain electrons  (Definitions on page 636)

Example 18.1 on page 637 and Practice.

Whenever one substance is oxidized, another substance must be reduced. 

Definitions on page 643.

The substance oxidized is the reducer/reducing agent.  The substance reduced is the oxidizer/oxidizing agent.

Example on page 642 – 645.  Practice problems on page 645.

Homework: Page 641, #5 and Page 651, #2 and Page 662, #18

12/3/09 (Thursday)

Essential Question: What is a galvanic/voltaic cell?

Half reactions:  Show only oxidation or reduction.  Electrons are listed as a reactant in a reduction half reaction and as a product in an oxidation half reaction.  Identify oxidizing agent and reducing agent.

2. Using overhead transparencies

anode: the location of oxidation (vowels)

    cathode: the location of reduction (consonants)

3. Sketch parts of cell: salt bridge/porous barrier, electrodes, solutions, external connections

    Also see page 653.  Page 663, #31 & 32 in class

4. Balancing by half-reaction.

Homework:  Electrochemical Cells prelab (Prelab = identifiers, purpose, safety, materials, draw a picture of experimental set up for one test.)

12/4/09 (Friday)

Electrochemical Cells lab.  Lab Report due Monday, 12/7.  Counts Twice.

AP Chemistry: Week of November 30

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

2. Balancing of equations

3. Mass and volume relations with emphasis on the mole concept

C. Equilibrium

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

2. Quantitative treatment

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

IV. Descriptive Chemistry

3. Introduction to organic chemistry: hydrocarbons and functional groups (structure, nomenclature, chemical properties)

Monday: Study for Acid-Base Test

Tuesday: Read Sections 25.2-25.4.  Know tables 25.1 & 25.2

Wednesday: Page 1098, #21

Thursday: Page 1098, #13, 17, 25, 27

Friday: Page 1098, #23, 24, 39 (Answers b,c backwards), 40, 41, 43, 51, 53 (draw only)

Semester Break assignment:  Nuclear Chemistry worksheet and study for solubility quiz.  Quiz will be first day back in January.

AP Chemistry: Organic Nomenclature notes and assignments

Organic Chemistry Nomenclature – I suggest vocabulary note cards.

 

Read Sections 25.2-25.4. 

Know tables 25.1 and 25.2

Know (make flash cards) for definitions of these words:

hydrocarbon

saturated hydrocarbon

unsaturated hydrocarbon

alkane

alkene

alkyne

aromatic hydrocarbons

normal  alkane = straight chain hydrocarbon

structural isomers

cycloalkane

geometric isomers

alkyl substitutions

addition reactions

hydrogenation

halogenation

benzene

toluene

xylene (two methyl groups)

naphthalene

Make one card for each prefix: meth, eth, prop, but, pent, hex, hept, oct. non, dec, dodec

Make one card for each prefix: sec-, tert-, iso, cyclo, cis, trans, ortho, meta, para

Make one card for each prefix: nitro, fluoro, chloro, bromo, iodo, phenyl

Table 25.4 on page 1071:  Make one card with class & functional group/suffix or prefix

Add:  thiol  Functional group — C — SH

 

alkanes: saturated hydrocarbons: Formula C_nH_(2n+2)

  normal (straight) See Table 25.1, page 1056

 

structural isomers: same formula, different structure Page 1057

substituent group (a substitution for one of the H).

derivative (compound with one or more functional/substituent group)

alkyl group - one less H than alkane  (Table 25.2 on page 1059) C_nH_(2n+1)

primary carbon - attached to one other C

secondary carbon - attached to two other C

tertiary carbon - attached to three other C

Naming rules and samples start on page 1058. Also halide substitutes (-F = fluoro for example)

 

Cycloalkanes (Page 1061)  C_nH_2n

Homework. Page  1098, #21

 

alkenes: double bond (model ethene), formula C_nH_2n

formula: # locates double bond (smallest # possible)

geometric isomers (cis, trans) and dienes

 

alkynes: triple bond (linear), formula C_nH_(2n-2)

formula: # located triple bond  (ethyne common name: acetylene)

alkenes & alkynes: same derivatives as alkanes.  Sample 25.3 & 25.4 on page 1064

Homework: page1098, #13, 17, 25, 27

aromatic hydrocarbon (contains a benzene ring).  See pg 1068

   Note: all carbon bonds in benzene ring are equivalent - resonance

  benzene is a planar molecule.

nitro (-NO₂) functional group

ortho (side by side), meta (skip one C), para (opposite) orientation for double derivatives.

xylene.= benzene with two methyl groups

phenyl (benzene as a functional group)

Special molecules: napthalene and trinitrotoluene.

 

Homework:   page 1098, #23, 24

 

 

See chart on page 1071. Add thiol. Examples pages 1072-1078

 

Homework:  page 1099, #39 (Answers b,c backwards), 40, 41, 43, 51, 53 (draw only)

AP Chemistry Assignments for Thanksgiving Break

Lab 14 report due Monday, 11/30

Acid-Base test one on Tuesday, 12/1

Homework for this unit:

* Net Ionic Equations Worksheet

* Chapter 16 problems: #17, 19, 21, 45, 47, 49, 53-59 odd, 65b, 73-85 odd, 91, 93, 95, 111

* Chapter 17 problems: #15ab, 17

* AP Worksheet

Answers:

5a. 4.0 x 10^-6 M

5b. 1.6 x 10^-10

5c.  6.2 x 10^-5

5d.  2.8 x 10^-2 M

6a.  1.6 x 10^-3 M and 1.1%

6b.  8.73

6c.  Q = 2.3 x 10^-11 and Q>K, so it precipitates.

 

 

Parents Please Help

We need tissues.  At the beginning of the year, I brought in one box and a parent sent one box.  Those two boxes have been consumed.  Donations of tissues will be appreciated.

Honors Chemistry: Week of November 16

GPS

SC1 Students will analyze the nature of matter and its classifications.

d. Use IUPAC nomenclature for both chemical names and formulas:

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

a. Identify and balance the following types of chemical equations:

• Synthesis

• Decomposition

• Single Replacement

• Double Replacement

  • Combustion

 

Monday: Activity of Metal lab

 

Tuesday: Complete lab report and Single Replacement Reactions worksheet.

 

Wednesday: Complete review assignment.  Note: Abstract portfolio project is due tomorrow.

 

Thursday: Abstract portfolio project due today.  Study for reactions test.

 

Friday: Reactions test today.  No homework.

AP Chemistry: Week of November 16

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

2. Balancing of equations

3. Mass and volume relations with emphasis on the mole concept

C. Equilibrium

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

2. Quantitative treatment

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: Page 713, #73, 75, 77 and Read Section 16.9 and complete prelab activity

Tuesday: Salt lab  (Due Thursday)

Wednesday: Complete salt lab report.  Page 714, #91, 93, 95, 111 and Page 759, #15ab, 17

Thursday: Prelab 14, AP acid-base problems worksheet, Nuclear Chemistry worksheet

Friday: Lab 14 (You will be doing only one unknown.)

Due Monday, 11/30:

Lab 14 Report (no Sources of Error)

AP acid-base worksheet (Review for Acid-Base test on Tuesday, 12/1)

AP Chemistry: November 11-13

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

2. Balancing of equations

3. Mass and volume relations with emphasis on the mole concept

C. Equilibrium

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

2. Quantitative treatment

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

Wednesday: Page 710, #17, 19, 21

Thursday: Pg 712, #45, 47, 49

Friday: Page 712, #53-59 odd, 65b

AP Chemistry: Acid-Base Unit notes and assignments

Acid/Base: Important class of reactions in industry and because they occur often in nature.

 

Self-ionization of water(Autoinoization)

Truth: H₂O + H₂O « H₃O⁺ + OH^-
Convenient Lie: H₂O « H⁺ + OH^-

H₃O⁺ = hydronium ion
H⁺ = hydrogen ion
OH^- = hydroxide ion

 

Electrolyte formation: Acids
Truth: HA + H₂O « H₃O⁺ + A^-
Convenient Lie: HA « H⁺ + A^-
Ionization

 

Electrolyte formation: Base
Cation(OH) « Cation⁺ + OH^-
(dissociation)

 B + H₂O « BH⁺ + OH^-
(B = base, BH⁺ = protonated base)
(ionization)

 

Acids react with active metals to produce hydrogen gas.

Salt: cation plus the anion of an acid

 

Acids react with active metals to produce hydrogen gas.
Acids react with carbonates and hyrdogen carbonates
to produce carbon dioxide and water.

 

Arrhenius neutralization:
acid + base ® water + salt

Bronsted Neutralization
acid + base ® protonated base + anion
HA + B ® BH⁺ + A^-

Bronsted conjugates

Acid:  HA ® Conjugate base: A^-

Base: B ® Conjugate acid: HB⁺

So……
An acid looses proton to become a conjugate base (ready to accept a proton)

And…..
A base gains a proton to become a conjugate acid (ready to loose a proton)

See pages 670-671.

 

Acid-base reaction

One substance donates a proton.

One substance accepts a proton.

Water can accept or donate a proton
(Recall autoionization.):  amphoteric, amphiprotic

 

Homework: Page 710, #17, 19, 21

 

Lewis definition

Acid = electron pair acceptor

Base = electron pair donor

 

 

pH

Logarithm Sigfigs are BEHIND the decimal.

Self-ionization of water

H₂0 + H₂O « H₃O⁺ + OH^-

 

K_w = [H₃O⁺] [OH^-] = 10^-14

 

[H₃O⁺] = [OH^-] = 10^-7 M

 

pthing = -log [thing]
pH = - log [H⁺]
pOH = -log [OH^-]
pK_a = -log K_a
pK_b = - log K_b

Acid: pH < 7, [H⁺] > 10^-7 M, pOH > 7

Base: pH > 7, [OH^-] > 10^-7 M, pOH < 7

 

Sample 16.6 on page 677.
Samples 16.7 -16.9

Homework:  Pg 712, #45, 47, 49

 

For HA ↔ H⁺ + A^-

Ka = [H⁺][A^-]/[HA]  (Table on page 1115)

 

Percent ionization formula on page 683.  Sample 16.11 on page 684

 

Ka problems:  Sample 16.10 on page 682.  Samples 16.12 & 16.13

 

For solutions of any weak acid, [H⁺] decreases as the initial concentration of the acid decreases, but the percent dissociation increases as the initial concentration of the acid decreases.

 

Homework: Weak Acid:  Page 712, #53-59 odd, 65b

 

Polyprotic acid – stepwise proton donation.  Sample 16.14 on page 689.  (For pH, don’t need Ka₂)

H₂SO₄ is a special case.  Must include Ka₂.

 

B + H₂O ↔ BH⁺ + OH^-

Kb = [BH⁺][OH^-]/[B]  (Table on page 1116)

Sample 16.15 on page 691

Types of weak bases on page 692

Sample and practice 16.16 on page 692

Homework:  Weak Bases:  Page 713, #73, 75, 77

 

Relationship of Ka and Kb (page 693)  Ka x Kb = Kw

Sample 16.17 on page 695

SO:  weak acid → strong conjugate base

Strong acid → weak conjugate base

Weak base → strong conjugate acid

Strong base → weak conjugate acid

Homework:  Read Section 16.9 and complete “Salt Hydrolysis” prelab

 

Salt hydrolysis lab. 

 

Salt problems:  Homework: Page 714, #79-85, odd

 

How is structure related to acid strength?

In general – the weaker the bond holding the p+ to molecule, the stronger the acid (Easier to remove the p+)

binary acid – stronger plar bond = weak acid. (HF hard to pull p+ from electronegative F)

oxyacid – more oxygen around central atom = stronger acid (e- pulled towards all those other oxygen and away from H)

    - if oxygen # is same: the more electronegative the center atom, the stronger the acid (highly electronegative center atom pulls the oxygen electrons toward it and away from H)

Is a metal oxide solution acidic or basic?  Basic  (Na₂O + H₂O ® 2 NaOH)

Is a nonmetal oxide solution acidic or basic? Acidic (SO₃ + H₂O ® H₂SO₄)

 

Homework:  Page 714, #91, 93, 95, 111

 

 

Common ion effect:  Samples 17.1  and 17.2 on page 720 – 722.

 

Homework:  Page 759, #15ab, 17

Prelab 14 (Ka) due Friday, 11/21.  Change procedure mass to 0.10 g – 0.15 g and you will only do one unknown

 

 

Thanksgiving week assignment (Nuclear Chemistry, Chapter 21).  Counts as graded (accuracy) homework twice.  Due Monday, November 30

 

AP Problem Set

Answers:

5a. 4.0 x 10^-6 M

5b. 1.6 x 10^-10

5c.  6.2 x 10^-5

5d.  2.8 x 10^-2 M

6a.  1.6 x 10^-3 M and 1.1%

6b.  8.73

6c.  Q = 2.3 x 10^-11 and Q>K, so it precipitates.

 

Test on Tuesday, 12/2

Honors Chemistry: Week of November 9

GPS

SC1 Students will analyze the nature of matter and its classifications.

d. Use IUPAC nomenclature for both chemical names and formulas:

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

a. Identify and balance the following types of chemical equations:

• Synthesis

• Decomposition

• Single Replacement

• Double Replacement

  • Combustion

 

Monday: Worksheet and classify reactions: Page 274, #32, 33

 

Tuesday: Net Ionic Equations Worksheet

 

Wednesday: Predict Products (on assignment sheet problems 1-11)

 

Thursday, 11/12 through Monday, 11/16: Group lab   (Lab report due Wednesday, 11/18)

 

Special note:  Portfolio: Google Abstract Project due on Thursday, 11/19

    Reactions Test on Friday, 11/20