Archive – Q3 –  week 8 – 18-19

week 8

Week of 3/25 – 3/29 – Please Refresh!

3/25 – Monday –  Period 2/3

1. Review Lecture on Integrated Formulas/concepts – video posted below
2. Crystal Violet and OH- Kinetics Lab.
Determine the order with respect to [CV] using graphs.

Period 4

1. Short Integrated Rate Laws Discussion with Tall teacher.
2. Rate Law Lab – CV and hydroxide lab
Kinetics 2 – rate law KEYp .pdf

Reference Table: This is the first order integrated formula. This is the second order integrated formula. There is no zero order integrated formulas on the AP. This is the Arrhenius equation that ties activation energy ( Ea) and temperature to the rate law constant.

#### Spectrophotometry

Crystal Violet: Chromophore – Conjugated molecular compound 3/25 – Monday HW:
1:  Please complete Kinetics 1 worksheet (side 2) and review with key
2:  Please complete Kinetics 2 worksheet (1st worksheet 1984B, question c and d)
and review with the key.
3.  Kinetics Lab is due tomorrow/ You may have completed in class.

4. Complete a 5 question MC form on rate law

Catalysts and Activation Energy (Ea = Activation Energy)
The Arrhenius equation calculations are not on the AP but the concepts of how the k (Rate law Constant, like the equilibrium constant) is related to temperature.

5.  Please watch the Lecture on the derivation of the half – life formulas and lecture on the
Activation Energy, Ea.
6. Complete the form below that is based on the 2 lectures.
Kinetics 1 – rate law.pdf

Kinetics 1 – rate law key.pdf
Kinetics 2 – rate law.pdf
Kinetics 2 – rate law KEYp .pdf
RATE LAW Lab requirements: YOU MAY HAND THIS AS LAB GROUP or individually

1: Title : Graphical Analysis of the reaction of CV and hydroxide
2: Objective; To determne the order of reaction with respect with CV.
3: Data:

Showing off – determining the half life will identify the order of the reaction.

a) I need 3 graphs. One that is the original vs time. This the one you did in class.

b) Second and Third = the other is either 1/[CV] vs time or ln[CV] vs time
Whichever is linear.  You will need to make 2 graphs. Pick the data points from the original

graph, one every 10 seconds (out of the total 200 seconds of data collected and convert to

1/[CV]
or
ln[CV]. Remember that absorbance is
proportional to
Molarity.

Use Logger Pro to generate a new

graphs from scratch. Go in order when you do so.  The graph that gives you a linear line will tell you           what order is.
c) Please write the Rate Law R = k [CV]m[OH]0 based on your graphs!

d) Make a statement about how you determined the order with respect with to [CV].

e) Remember that the OH- does not significantly change because it is about 1000x greater in Molarity

than the CV THus it is staying relatively constant!

f) Calculate or determine the rate law constant (k) with units.

Initial concentrations:  [CV]: 2.5 x 10-5 M  and

[OH-]: 0.1 M
1.5 ml of

[CV] and 1.5 ml of

0.1 M of OH  in cuvette.

Today’s Logger Pro Class Files for the above lab:

Lynch Ferrantino Graph P4.cmbl
period2.AshleyandJohn.cmbl

period 2 group your names AAAA.cmbl

Period 2- Triple J.cmbl
Period 4 Bella and Sophie .cmbl
period four- courtney, emily, edona, jane, jackie.cmbl
toni&jay.cmbl
Jade and Tristian Show.cmbl
This Form is Live NOW 3/25!

#### Rate Law MC Review Questions 1718

Derivation of half – life formulas:

Activation Energy Lecture:

Half Life Activation Energy (Ea) Form:
This Form is Live NOW 3/25!

#### Half Life / Arrhenius / Ea Form 1718

INTEGRATED CALCULATIONS LECTURE – HW rate Law problem reviewed:
KSP REVIEW of 2 AP Free response Problems (today after school) –
Rate LAW presentation:

#### Rate Law

Period 2 – Lecture review of Integrated Rate law Equations

3/26 – Tuesday – period 2 –

1.  40 minute – part 2 question test – 1 Ksp and 1 Rate Law part 2 question. (40 minutes)

period 3/4 –

1. 40 minute part 2 question test – 1 Ksp and 1 Rate Law part 2 question. (40 minutes)
2.  test review –
3.  Half Life – half life of [CV] lab.

3/26 – Tuesday Homework: Acid Base Basics Lecture

1. review the test with video that will be posted below or keys:

2. Watch the Acid/Base Basic lecture 1 – THIS IS REVIEW!!!!!

I will be directing you to the Acid and Bases Intro packet Key p.pdf where needed in the form.

3.  Watch the Acid/Base Basics Lecture 2 – New (equilibrium)
4.  Complete the Form.
We did the Acid and Bases Intro packet in November! You may want to look through the key of this packet to help stir the acid/base knowledge.

I will be directing you to the Acid and Bases Intro packet Key p.pdf where needed in the form.
 Acid and Bases Intro packet new.pdf Acid Base 2 – Ph Ka.pdf Acid and Bases Intro packet Key p.pdf View Download Acid Base 2 – Ph Ka key.pdf feeling spacey..
Acid Base 1a – Table of Acid and Base Strength.pdf

Today’s Test Reviewed:
Acid Base Basics –

Acid/Base Basic lecture 1

Acid/Base Basics Lecture 2

Screencast lecture of acid/base basics 1:
ACID BASE Basics 1 and 2 Form:

#### ACID BASE Basics Form

Lecture for Acid Base 2 – Ph Ka.pdf worksheet, which would help for the last 2 questions in the above form.

3/27 – Wednesday – period 2/3 –
1.  KSP/rate law Test Rate Law Review

2. Iodine Clock Rate Law demo and test (mechanism from Rate Law presentation)

3.  Keq, Ka, Kb and the multiplication of Equilibrium constants: Form review last week

Today’s demo:
3/27 – Wednesday – Homework: NO Homework Tonight

3/28 – Thursday – period 2 –

1.  Half Life, Arrhenius Equation – factors that affect rate law constant- half life of [CV] lab.

2.  Keq, Ka, Kb and the multiplication of Equilibrium constants: Form review last week

3.  Acid/Basics reviewed

Acid Base basics – Important acid base skills needed -THIS IS A REVIEW!!! WE did this in November!!

A) Auto Ionization of water:              H2O  <->  H+  +   OH
H2O + H2O  <-> H3O+  +  OH

B) Acid Base Definitions (Arrhenius,  Bronsted Lowry,  Lewis)
C) pH and pOH determination, Kw = [H+/H3O+] [OH] = 1 x 10-14
D) pKw =pH  + pOH
E) Kw = Ka x Kb  or pKw = pKa  +  pKb
F) Strength of Acids = Ka – acid dissociation constant (equilibrium constant for acid conjugate base equilibria)
G) Strong Bases

4. Note taking on 2 titrations – 5 points

Titration curves revisited:
Strong Acid/Base Titration Review:
5.Henderson Hasselbach equation – Buffers
Titration curves revisited for notes:
Strong Acid/Base Titration Review:

Weak acid /strong base titration review

HC2H3O2      +       OH      —–>    _________   +   H2O
?M, 25 ml              0.10M

period 3/4 –

1.  Keq, Ka, Kb and the multiplication of Equilibrium constants: Form review last week

2.  Acid/Basics reviewed

3. Note taking on 2 titrations

Titration curves revisited:
Strong Acid/Base Titration Review:
4.Henderson Hasselbach equation – Buffers

3/28 – Thursday  Homework:
1. Complete your notes on the Strong Acid/ Base Titration started in class.

Use the lecture posted below: It will be up in the afternoon.

2. Complete your notes on the Weak Acid/ Strong Base Titration started in class (period 4) or not started (period 2) with lecture below.

You need to view explanation for points 3 and 4 to complete the back page of the homework. If cannot get to the whole video thats ok but please get to points 3 and 4!

You really need to view point 3 and 4 to answer the back page of the homework

Use the lecture posted below: It will be up in the afternoon.

2. Please complete the Acid Base 8 – Titrations.pdf  worksheet and review with the key.

You need to view explanation for points 3 and 4 in the SECOND LECTURE to complete the back page of the homework. If cannot get to the whole video thats ok but please get to points 3 and 4!

Acid Base 8 – Titrations.pdf

Acid Base 8 – Titrations Key p.pdf

Strong Acid /Strong Base Note Taking Lecture:

Weak Acid /Strong Base Note Taking Lecture:

You need to view explanation for points 3 and 4 in the SECOND LECTURE to complete the back page of the homework. If cannot get to the whole video thats ok but please get to points 3 and 4!

3/29 – Friday – period 2/3 –

1. Review of lecture last night using notes of

Review points 3 and 4 of titration curve
Acid Base 8 – Titrations.pdf

Acid Base 8 – Titrations Key p.pdf
2.  NH4Cl  titration with strong base (0.10 M NaOH)

25.0 ml NH4Cl titrated with 0.10 M NaOH
3. Started lab write- up – requirement posted below in HW.
period 4-

1. NH4Cl  titration with strong base (0.10 M NaOH)

25.0 ml NH4Cl titrated with 0.10 M NaOH
TODAY’s TITRATION –
NH4Cl  titration with strong base (0.10 M NaOH)

25.0 ml NH4Cl titrated with 0.10 M NaOH

We did not get to this but it would serve you well to review the key to this worksheet (Determining pKa and Indicators.pdfas it it will review how we determine the appropriate indicators for titrations.  We did complete it November but now it will mean more.  Remember that we determine Equivalence points (stiochiometric endpoints: H+ = OH )  by pH probes AND we estimate Equivalence points by determining the “end point” of  titration by using acid base indicators (that are weak acid conjugate pairs themselves.

Determining pKa and Indicators.pdf

Determine Ka and Indicator key p.pdf
3/29 – Weekend Homework:

1.  Complete the Ammonium Chloride Lab. I will post a video on how to verify the points 1 – 5.
Please complete the calculations on the printed graph!
On Tuesday next week you will be taking a test on how to predict a titration curve, plotting all 5 points from          given data (You will be working in the reverse with a given concentrations and Ka.

Please identify the following from the Titration curve of the NH4Cl
A) Net ion Reaction for the Titration (Driven)

B) Net ion reaction for the NH4Cl in water.

C) Calculation that determines the concentration of the NH4Cl

D) Calculate the Ka of the acid.

E) Verify the following 5 points on the Titration curve:

1) initial pH (in side the beaker BEFORE IT IS titrated) – pH at zero volume.
2) Half equivalence point  – volume and pH
3) a point in the buffer region  USE 22 ml of base added
4) Equivalence point – Volume and pH
5) Final pH – pH at the End of titration

2
.  Please complete the
Determining pKa and Indicators.pdf worksheet below with the lecture below and or key below.

Determining pKa and Indicators.pdf

Determine Ka and Indicator key p.pdf

Determining pKa and Indicators.pdf should look familiar!
The point of the worksheet is to derive and use the Henderson Hasselbach equation for point #2 in titration
problems and to review that acid/base indicators (chromophores with pi stacking!!!!!!) are also acid base buffer       solutions.  Deciding which indicator to use is based on their individual Ka that best intersects the asymptotic
region that is closest to equivalence point.

We determine Equivalence points (stiochiometric endpoints: H+ = OH )  by pH probes AND we estimate Equivalence points by determining the “end point” of  titration by using acid base indicators (that are weak acid conjugate pairs themselves.
REMEMBER THAT INDICATORS provide us as approximation
of the equivalence point called an endpoint!

We write indicators in acid base chemistry with the following designation:

HIn    <—–>    H+    +        In
Conjugate Acid                                    Conjugate Base
* In the above equation, the colors are represented correctly of the acid/base indicator Litmus.
What makes them so important is these weak acid/base equilibrium solutions (indicators) have different colors in their conjugate acid and conjugate base form. The molecular structure of these macromolecules allosterically change their amount of conjugation (amount of double – single bonds) in the presence of H+ or OH.

When an appropriate acid / base indicator is used in a titration its color change occurs when there is about 50% of  HIn and 50% In is present.  This is the Half- equivalence point, which is when the ph = pka of the indicator!!!
Determining pKa and Indicators lecture:

Ammonium Chloride Titration lecture:

Play in youtube and under the description you can click on the timecode to take you to the
point in the lecture you want to review.