AP Chem – Q1 – week 3 – 22-23 | Mr. Grodski Chemistry

Q1 : Week 3 – 9/18 – 9/22

<- Week 2 – Week 4 -> Jump to: Tuesday, Wednesday, Thursday, Friday

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If you have not already please join the REMIND for this class.

Please Make sure Your read all instructions for all assignments.

LAB 1 – Gerber Voltaic Cell is DUE!!!!!

LAB 2 – Voltaic Cell design is due Tuesday 9/26

______________________________________________________ Jump to: Monday Homework 9/18 – Monday – A Day – 2/3a Lab, 4

Main focus –

a) To identify the voltage change in a voltaic cell due to Le Chatelier’s Principle with changes in the concentrations of ions in half cells, specifically in a concentration cell

b) To review the AP problems that introduce different voltaic cell designs.

c) To review review the errors in Lab 1.

d) To take the second Voltaic Cell quiz

Voltaic Cell quiz 1 key.pdf View Download

Period 2, 4:

1. Review of Homework released questions – Does the anode always get oxidized?

Recent Voltaic Cell AP Test Questions key p.pdf
View Download

2. Concentration Cell – Voltaic cells of our nervous system!!

Concentration Cell:

Cu⁰ (s) + Cu⁺² —–> Cu⁺² + Cu⁰

So only the Cu⁺² ions and their concentration changes that can create a stress that will cause the reaction to shift (become more favorable). If there is no change in the concentrations in either the oxidation cell or the reduction cell then there is no spontaneity or no voltage. This voltaic cell can be manipulated by LeChatelier’s Principle by adding a

A) COMMON ion (ex. CuCl2)

B) an ion that will precipitate out Cu⁺²

C) water to one side that will dilute the molarity the concentration of Cu⁺²

Positive volts = Favorable Pathway = Spontaneous = entropy of universe (∆S) increasing

(∆S) increasing= energy dispersed = obtain Free Energy (∆G) to do work (power our phones!)

Concentration Cells in our bodies!!

Today’sDemo: Set up a concentration cell with same concentration of copper (II) nitrate in both half cells and in the salt bridge.

– I added more copper (II) ions into the reduction half cell = INCREASED VOLTAGE.

– I added water into the oxidation half cell = INCREASED VOLTAGE

– I added sodium carbonate into the oxidation half cell = INCREASED VOLTAGE

3. Voltaic Cell Quiz – (Last 15 minutes)

Period 3a:

1. Conclusion writing – Lab 1

2. Lab 2 intro/explanation

Today’s Demo – What if I create voltaic cell with the same electrodes (Cu) and the same concentration of Copper ions?

Left Half Cell = Cu/ 0.1 M Cu(NO₃)₂

Right Half Cell = Cu /0.1 M Cu(NO₃)₂

Salt Bridge : 0.1M Cu(NO₃)₂

Stress 1: Add CuCl₂ (s) to left beaker

Stress 2: Add H₂O to right beaker

Do these 2 stresses counteract each other?

Today’s lesson on the concentration cell:.

__________________________________________________ Lab 1 – The Gerber Voltaic Cell

Voltaic Cell Lab 1 – Making of batteries (voltaic or galvanic cell) – In this Lab each person will make a pair of voltaic cells that if successfully created will power a 3 volt transistor radio.

LAB 1 – Voltaic Cell.pdf

View Download

–Error Analysis for the conclusion:

Chemical reactions that may have contributed:

Mg + 2HOH (water) —–> Mg⁺² + 2OH^– + H₂ (g)

Would these ions (Mg⁺² + 2OH^–) form a precipitate with ions already present? The color of the entire battery was bluish? What does that say about movement of Cu⁺² ions?

What factors were competing? Based on the experimental voltage which factor dominated?

Conclusion Writing:

1. What did find or measure Quantitatively? What are the important values of your data? This is normally posted in your results section of a formal writeup. How accurate are you (how close are you to a known standard, E⁰ cell )?

2. Make the leap! = connect your quantitative value and comparison with the known standard in terms of atom/ions or particle to explain a possibly reason for the outcome.

3. Error discussion.

Every laboratory is limited in errors in measurement and human errors. Do not write about these!! Please describe in detail every major limitation of this laboratory and why you believe it may have lead to your outcome.

IN this Lab the error discussion will result from things that are NOT FROM YOUR LEAP! Do nor just list errors. I want an explanation how these errors could of resulted in YOUR OUTCOME.

Lab 1 Conclusion review:

1. Please tell me what you measured (voltage) and calculated (percent error). Do not mince words. Get to the point. This is like our results section last year in our formal labs.

2/3: Explain your errors (why your percent error was so low or negative). You will combine the leap with the error analysis here. The leap last year was always about an organism and the leap this year is always about atoms or ions. So what did the atoms or ions do that may have contributed to the large negative error? There is one error that is the largest and I like to think of it as a love triangle between Mg, Cu⁺² , and H₂O.

___________________________________________

Review of the Lab 1 that might help with conclusion:

Gerber Voltaic Cell Time Lapse: I use this to review conclusion questions.

_____________________________________________________ jump to: top

9/18 – Monday’s Homework: –

1. Please work on finishing Lab 1 – DUE Wednesday 9/20 in the purple crate in front of the class. I did post a video review of the lab if you still need more help in the error analysis of the conclusion.

2. Please read the notes below, the animation AND THE VIDEO below, 12 volt car battery (lead acid) battery which is oldest and the most utilized battery in the cat industry UNLESS its an electric car (Lithium Ion).

3. Complete the form below on battery in your car (lead acid) UNLESS

its an electric car (Lithium Ion). You have a total of 3 submissions to this form.

How It Works

Let me give you the big picture first for those who aren’t very detail oriented. Basically, when a battery is being discharged, the sulfuric acid in the electrolyte is being depleted so that the electrolyte more closely resembles water. At the same time, sulfate from the acid is coating the plates and reducing the surface area over which the chemical reaction can take place. Charging reverses the process, driving the sulfate back into the acid. That’s it in a nutshell, but read on for a better understanding. If you’ve already run from the room screaming and pulling your hair, don’t worry.

The electrolyte (sulfuric acid and water) contains charged ions of sulfate and hydrogen. The sulfate ions are negatively charged, and the hydrogen ions have a positive charge. Here’s what happens when you turn on a load (headlight, starter, etc). The sulfate ions move to the negative plates and give up their negative charge. The remaining sulfate combines with the active material on the plates to form lead sulfate. This reduces the strength of the electrolyte, and the sulfate on the plates acts as an electrical insulator. The excess electrons flow out the negative side of the battery, through the electrical device, and back to the positive side of the battery. At the positive battery terminal, the electrons rush back in and are accepted by the positive plates. The oxygen in the active material (lead dioxide) reacts with the hydrogen ions to form water, and the lead reacts with the sulfuric acid to form lead sulfate.

The ions moving around in the electrolyte are what create the current flow, but as the cell becomes discharged, the number of ions in the electrolyte decreases and the area of active material available to accept them also decreases because it’s becoming coated with sulfate. Remember, the chemical reaction takes place in the pores on the active material that’s bonded to the plates.

from: https://www.batterystuff.com/kb/articles/battery-articles/secret-workings-of-a-lead-acid-battery.html

___________________________________________

________________________________________________

Lead Acid Battery Presentation :

Lead Acid Battery Animation :

Lead Acid Battery Tutorial :

In the Lead Acid Battery:

PbO₂(s) + HSO^–₄ (aq) + 3H⁺ (aq) + 2e^– —> PbSO₄ (s) + 2H₂O (l) E⁰ = + 1.69 V

PbSO₄(s) + H⁺ (aq) + 2e^– —-> HSO₄^– (aq) + Pb (s) E⁰= – .35 V

In your AP Reference Table: Pb⁺² + 2e^– —-> Pb⁰ E⁰= – .13 V

Lead Acid Form: This form is based in the information above. You have 3 more submissions tonight.

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Jump to: Tuesday Homework / top
________________________________________
9/19 – Tuesday – B Day – 2/3b Lab, 4

Main focus–

a) To Review the Lead Acid Battery

b) To Begin the design of Lab 2 – design a voltaic cell.

Period 2,4:

1. Review of Voltaic cell Quiz.

Voltaic Cell Quiz 2 – 22-23 KEY.pdf

View Download

2. Review the Lead Acid Battery HW Form- with key

– Implications for your voltaic cell design.

Lead Acid Battery Form 23-24 – KEY.pdf
View Download

In the Lead Acid Battery:

PbO₂(s) + HSO^–₄ (aq) + 3H⁺ (aq) + 2e^– —> PbSO₄ (s) + 2H₂O (l) E⁰ = + 1.69 V

PbSO₄(s) + H⁺ (aq) + 2e^– —-> HSO₄^– (aq) + Pb (s) E⁰= – .35 V

In your AP Reference Table: Pb⁺² + 2e^– —-> Pb⁰ E⁰= – .13 V

PbO₂(s) + HSO₄^–(aq) + 3H⁺(aq) + 2e^–—> PbSO₄ (s) + 2H₂O (l) E⁰ = + 1.69 V

HSO₄^–(aq) + Pb (s) —> PbSO₄(s) + H⁺(aq) + 2e^–E⁰= + .35 V ______________________________________________________________

PbO₂(s) + 2HSO₄^–(aq) + 2H⁺(aq) + Pb (s) —> 2PbSO₄(s) + 2H₂O (l) +2.04 V

Lead Acid Battery Diagram:

2. Lab 2 design – Complete your design and begin presentation in YOUR Google Slide that was linked to you in your School email account.

a) Complete slides 1 – 4 : See the Lab 2 requirements below.

– Tomorrow we will run the lab and see you has the POWER (high power to mass ratio! We are looking for the highest average volts

Period 3b:

1. LAB 2 Design – Begin your design and engineer the best single battery that will produce the greatest average voltage in 30 seconds.

2. Complete slides 1 – 4 in your presentation.

_________________________________________________________ Lab 2 – The Voltaic Cell STEM Lab

LAB 2 – design a voltaic cell with greatest voltage– modest breakfast up for grabs

Voltaic Competition – Lab 2.pdf View Download

Given the following electrodes: Sn, Cu, Zn, Fe, Al

and solutions:

sodium hydroxide, copper (II) sulphate, tin (II) chloride,

iron (III) chloride, aluminum nitrate, zinc nitrate

Students gather their materials and design their battery. Design needs to be in the lab groups presentation before they begin. Lab 2 – This is a slide-up lab done per each individual student. Please follow instructions:

This Lab write-up is NOT a group slide-up. There is one presentation for every individual.ab group. I have emailed everyone with their individual link.

You need to present on the slides in the Presentation the following:

1. Title page with all Lab partners listed.

2. Objectives.

3. Materials Page listed with all available components

4. Labeled Diagram Slide of proposed voltaic cell design – Draw a diagram with your phone

A) labeled anode and cathode and identity of metals

B) direction of the flow of electrons.

C) all available ions present

D) salt in salt bridge – and ion flow

E) Charge on the electrodes

F) Half reactions for each half cell

G) Overall net ion equation

H) E^o cell

5. Labeled Diagram Slide of actual voltaic cell design – Use a picture you took with your phone Label as you did in #4

6. Diagram of manipulations of Spontaneity – U diagram, LeChateliers principle chart

7. Best Measured voltage (need a picture or video with the battery).

8. Discussion section of why your design or choice of materials lead you to your results. Chemical reactions are needed (overall reaction) as well as any side reactions that were competing, Why was you final choices better than your original

______________________________________________________ Jump to: top 9/19 – Tuesday Homework: –

1. Complete slides 1 – 4 based on the requirements posted above for Lab 2.

2. Alkaline battery assignment:

a) Please view the video on how the Alkaline battery is made.

b) Please view the animation of the alkaline battery and the half reactions for this household battery.

c). Please complete the Alkaline Form.

1: How Alkaline Batteries are made :

Alkaline Battery Animation :

In the Alkaline Battery:

Inner half Cell:

ZnO (s) + H₂O (l) + 2e^–→ Zn (s) + 2OH^– (aq) (E° = – 1.28 V)

Outer half Cell:

2MnO₂ (s) + H₂O (l) + 2e^– → Mn₂O₃ (s) + 2OH^– (aq) (E° = + 0.15V)

https://electricalengineering123.com

Alkaline Battery Form: This form is based in the information above. You have 3 submissions.

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Jump to: Wednesday Homework / top ______________________________________________ 9/20 – Wednesday – A Day – 2, 3a/4 Lab

Main focus –

a) To Construct a Voltaic cell with greatest sustained voltage in 30 seconds.

Period 2,3: Lab both periods

1. (Period 2) – Review of the Alkaline Battery Form with key below:

Alkaline Battery Form – Key 22-23 .pdf
View Download

2. Construct your voltaic cell based on your plan that you and your lab group decided on last night

a) Test your Voltage of that cell. (take pictures of your cell for the slide presentation (slide-up)

b) Make adjustments to that cell to improve it. You may need to identify other factors that you did not consider in the your first design.

c) Complete your final design and record your sustained voltage for 30 secs.

Include the video and still pics of the final design in you slide-up.

Period 4:

1. Same as above except you will only really get to build and test your design.

_________________________________________________________ Lab 2 – The Voltaic Cell STEM Lab

LAB 2 – design a voltaic cell with greatest voltage– modest breakfast up for grabs

Voltaic Competition – Lab 2.pdf View Download

Given the following electrodes: Sn, Cu, Zn, Fe, Al

and solutions:

potassium hydroxide, copper (II) sulphate, tin (II) chloride,

iron (III) chloride, aluminum nitrate, zinc nitrate , sodium carbonate

This Lab write-up is NOT a group slide-up. There is one presentation for every individual.ab group. I have emailed everyone with their individual link.

You need to present on the slides in the Presentation the following:

1. Title page with all Lab partners listed.

2. Objectives.

3. Materials Page listed with all available components

4. Labeled Diagram Slide of proposed voltaic cell design – Draw a diagram with your phone

A) labeled anode and cathode and identity of metals

B) direction of the flow of electrons.

C) all available ions present

D) salt in salt bridge – and ion flow

E) Charge on the electrodes

F) Half reactions for each half cell

G) Overall net ion equation

H) E^o cell

5. Labeled Diagram Slide of actual voltaic cell design – Use a picture you took with your phone Label as you did in #4

6. Diagram of manipulations of Spontaneity – U diagram, LeChateliers principle chart

7. Best Measured voltage (need a picture or video with the battery).

______________________________________________ Jump to: top 9/20 – Wednesday Homework: –

LAB 1 is due ! Please place it into the Purple Crate tomorrow morning.

1. Lab 2 write-up (slide – up): I have sent every lab group their individual link to a blank Google Presentation through their SCHOOL email. Please open the link and begin working on your slides of your individual presentation.

IF YOU CANNOT OPEN THE LINK YOU NEED TO MAKE SURE YOU ARE SIGNED INTO GOOGLE WITH THE EMAIL ACCOUNT THAT THE LINK WAS SENT.

Your group needs to complete AT LEAST 1 – 5 for Thursday: 6 – 8 will be for Friday?

1. Title page with all Lab partners listed.

2. Objectives.

3. Materials Page listed with all available components

4. Labeled Diagram Slide of proposed voltaic cell design – Draw a diagram with your phone

A) labeled anode and cathode and identity of metals

B) direction of the flow of electrons.

C) all available ions present

D) salt in salt bridge – and ion flow

E) Charge on the electrodes

F) Half reactions for each half cell

G) Overall net ion equation

H) E^o cell

5. Labeled Diagram Slide of actual voltaic cell design – Use a picture you took with your phone Label as you did in #4

6 – 8 will be Thursday Night’s Homework_

6. Diagram of manipulations of Spontaneity – U diagram, Le Chateliers principle chart

7. Best Measured voltage (need a picture or video with the battery).

________________________________________________

Jump to: Thursday Homework / top
____________________________________________________________________ 9/21 – Thursday – B Day – 2/3b Lab, 4

Main focus –

a) To build a voltaic cell with the greatest sustained voltage in 30 seconds

Period 2

1. Continue with LAB 2 – Voltaic cell Competition –

Voltage Tests Today!!!!

Period 3b,4 –

1. Review of the Alkaline Battery Form with key below:

Alkaline Battery Form – Key 22-23 .pdf
View Download

2. Continue with LAB 2 – Voltaic cell Competition –

You will have 2 periods today to compete your design and record your voltage.

Voltage Tests Today!!!!

D) Performed the demonstration.

_________________________________________________________ Lab 2 – The Voltaic Cell STEM Lab

LAB 2 – design a voltaic cell with greatest voltage– modest breakfast up for grabs

Voltaic Competition – Lab 2.pdf View Download

Given the following electrodes: Sn, Cu, Zn, Fe, Al

and solutions:

potassium hydroxide, copper (II) sulphate, tin (II) chloride,

iron (III) chloride, aluminum nitrate, zinc nitrate , sodium carbonate

This Lab write-up is NOT a group slide-up. There is one presentation for every individual lab group. I have emailed everyone with their individual link.

You need to present on the slides in the Presentation the following:

1. Title page with all Lab partners listed.

2. Objectives.

3. Materials Page listed with all available components

4. Labeled Diagram Slide of proposed voltaic cell design – Draw a diagram with your phone

A) labeled anode and cathode and identity of metals

B) direction of the flow of electrons.

C) all available ions present

D) salt in salt bridge – and ion flow

E) Charge on the electrodes

F) Half reactions for each half cell

G) Overall net ion equation

H) E^o cell

5. Labeled Diagram Slide of actual voltaic cell design – Use a picture you took with your phone Label as you did in #4

6. Diagram of manipulations of Spontaneity – U diagram, LeChateliers principle chart

7. Best Measured voltage (need a picture or video with the battery).

What did the chemicals do to help or inhibit your intended outcome?

___________________________________________________ Jump to: top 9/21 – Thursday Homework: –

1. Complete your Slide-up of Lab 2 using the guidelines above – DUE TUESDAY 9/26

In your Discussion section you must now explain what you did to attain the highest voltage and how did that affect the spontaneity of the forward reaction? What were the consequences and how did the chemicals behave? What was the leap???? Explain all competing processes.

I will have your videos and winners posted tomorrow morning..