Archive – Q2 week 3 – 20 – 21
Week of 11/30 – 12/4 – Please Refresh every time you open– this page is changing often!
The 4 day – A, B, C, D cycle looks like this:
Day Period
2 3 4
In class: A Lab Lab Single Class
Remote: Lab Lab Single Class
Monday In class: B Single Class LAB LAB
Remote: Single Class LAB LAB
In class: C Single Class LAB LAB
Remote: Single Class LAB LAB
In class: D Lab Lab Single Class
Remote: Lab Lab Single Class
This weeks 5 day Schedule:
11/30 – Monday – “B” Day –period 2, – I 2(B,D) 3(D) AP CHEMISTRY
– period 2, – R 2(B,D) 3(D) REMOTE INSTRUCTION
-period 3,4 (LAB) – I 3(B) 4(B,D) AP CHEMISTRY
-period 3,4 (LAB) – R 3(B) 4(B,D) REMOTE INSTRUCTION
12/1 – Tuesday – “C” Day – period 2, – I 2(A,C) 3(A) AP CHEMISTRY
–period 2, – R 2(A,C) 3(A) REMOTE INSTRUCTION
-period 3,4 (LAB) – I. 3(C) 4(A,C) AP CHEMISTRY
-period 3,4 (LAB) – R 3(C) 4(A,C) REMOTE INSTRUCTION
12/2 – Wednesday- “D” Day – period 2,3 (Lab) – I 2(B,D) 3(D) AP CHEMISTRY
– period 2,3 (Lab) – R 2(B,D) 3(D) REMOTE INSTRUCTION
-period 4 – I 3(B) 4(B,D) AP CHEMISTRY
-period 4 – R 3(B) 4(B,D) REMOTE INSTRUCTION
12/3 – Thursday “A” Day – period 2,3 (Lab) – I 2(A,C) 3(A) AP CHEMISTRY
–period 2,3 (Lab) – R 2(A,C) 3(A) REMOTE INSTRUCTION
-period 4 – I 3(C) 4(A,C) AP CHEMISTRY
-period 4 – R 3(C) 4(A,C) REMOTE INSTRUCTION
12/4 – Friday- “B” Day –period 2, – I 2(B,D) 3(D) AP CHEMISTRY
– period 2, – R 2(B,D) 3(D) REMOTE INSTRUCTION
-period 3,4 (LAB) – I 3(B) 4(B,D) AP CHEMISTRY
-period 3,4 (LAB) – R 3(B) 4(B,D) REMOTE INSTRUCTION
11/30 – Monday – “B” Day –period 2, – I 2(B,D) 3(D) AP CHEMISTRY
– period 2, – R 2(B,D) 3(D) REMOTE INSTRUCTION
-period 3,4 (LAB) – I 3(B) 4(B,D) AP CHEMISTRY
-period 3,4 (LAB) – R 3(B) 4(B,D) REMOTE INSTRUCTION
The Blue team and the Orange team are remote. Please move to the Remote instruction page.
Period 2 , Period 3 :
1. Review Acid Base Test 2 (taken Last Tuesday) –
I will have emailed you your graded test 2 for your review this morning
2. Tum’s Lab set-up notes. (This will be a formal lab).
Lab 13 – Determination of active ingredient in TUMS (750 EXTRA!) –
Note- taking – You will need these note to complete your procedure of lab 13.
Lab 13 – Determination of active ingredient in TUMS (750 EXTRA!) –
Period 4:
a) Standardize the Base!
b) Perform the lab based on YOUR procedure!
1) Crush Tabs (2)
2) Add excess acid
3) Titrate Excess
4) Calculate the milligrams per tablet.
Today’s Lesson – Tum’s Back Titration Lab Setup –
11/30 – Monday – “B” Day – Homework –
1. Please compete the form below that reviews the concepts from Test 1 and 2.
You will only have 2 submissions! Make them count!
End of Monday..
12/1 – Tuesday – “C” Day – period 2, – I 2(A,C) 3(A) AP CHEMISTRY
– period 2, – R 2(A,C) 3(A) REMOTE INSTRUCTION
-period 3,4 (LAB) – I. 3(C) 4(A,C) AP CHEMISTRY
-period 3,4 (LAB) – R 3(C) 4(A,C) REMOTE INSTRUCTION
The Red team and the Green team are remote today. Please move the remote section today.
Period 2:
Notes on the lab:
Standardization of the Strong base in this back titration of TUMS.
In this analysis of the “active ingredient” of Tums ( CaCO3 ) we will need to use a strong base to titrate the excess HCl that was used to drive the reaction to completion:
Net Ion: 2H+ (aq) + CaCO3 (s) —> CO2 (g) + H2O (l) + Ca+2
Excess
The excess Strong Acid will drive the reaction to completion due to Le Chateliers Principle. It also important to to have excess Strong Acid to react with all the CaCO3 that will be mixed and “hidden” with the binder, coloring, flavor, and etc. That is why it is important to crush the tablets (tabs!) with a mortar and pestle in order to expose all of the salt, CaCO3 to the acid.
Now after we add the excess acid we will have to Titrate this excess acid with a Strong Base. This lab produces incredibly accurate results ONLY IF OUR SOLUTIONS that we use ARE ACCURATE. We are adding 0.04 moles of protons from the 100.0 ml of a 0.4 M HCl solution. Because we are adding about 0.01 moles of extra protons from the strong acid we need to titrate the excess protons with a strong base AND that solution needs to verified or STANDARDIZED.
I made a 0.5 M NaOH solution. I was very careful to make this solution BUT because strong Bases are very reactive that solution is definitely LOWER in concentration as the hydroxide reacts with the CO2 (Lewis Acid) in the air. I used 20 grams of solid NaOH (.5 mole) dissolved in a 1 liter of solution to make a 0.50 M NaOH solution
BUT not all of the solid is NaOH as CO2 from the air will cause the NaOH to become Na2CO3. This also happens in solution. Strong bases are carbon dioxide scrubbers that are used to remove it from space capsules.
2NaOH(s) + CO2 (g) —–> Na2CO3 + H2O
Also NaOH is deliquescent which means it can absorb water from the air and start dissolving itself. This would add weight to the Base and dilute is quantity.
Because NaOH has these issues we need to verified or STANDARDIZE it with a weak acid that is not reactive and does not have these issues. A perfect solution to this (no pun intended!) is using KHP. Potassium Hydrogen Phalate.
KHP, (KHC8H4O4) is excellent to standardize a Strong Base with because it
1. Weak Acid – thus does not react unless forced to by a Strong Base
2. Is a solid – we eliminate volume errors when making this solution
3. It has a large molecular mass (204 g/mol) – measurement errors with a large
molecular mass will not lead
to large mole errors.
Net Ion: HC8H4O4– + OH– —-> C8H4O4– 2 + H2O
You will find from this standardization that my solution of 0.50 M NaOH is less but we need to know its exact value to proceed with the lab.
Lab 13 – Determination of active ingredient in TUMS (750 EXTRA!) –
a) Standardize the Base!
b) Perform the lab based on YOUR procedure!
1) Crush Tabs (2)
2) Add excess acid
3) Titrate Excess
4) Calculate the milligrams per tablet.
Period 3,4 (LAB)
1. Notes on Lab – Standardization –
2. Run the lab
Lab 13 – Determination of active ingredient in TUMS (750 EXTRA!) –
a) Standardize the Base!
b) Perform the lab based on YOUR procedure!
1) Crush Tabs (2)
2) Add excess acid
3) Titrate Excess
4) Calculate the milligrams per tablet.
Period 4 – Lab 13 – Calculations Review –
12/1 – Tuesday – “C” Day – Homework
1. Please complete the following worksheet and review with the key.
12/2 – Wednesday- “D” Day – period 2,3 (Lab) – I 2(B,D) 3(D) AP CHEMISTRY
– period 2,3 (Lab) – R 2(B,D) 3(D) REMOTE INSTRUCTION
-period 4 – I 3(B) 4(B,D) AP CHEMISTRY
-period 4 – R 3(B) 4(B,D) REMOTE INSTRUCTION
The Blue teams and the Orange Team are remote today. Please move to the Remote Instruction page.
Period 2,3 (Lab) –
1. Review Monday’s form –
2. Solutions concepts – this will help with part 1 of the Lab procedure
3. Run the Lab
Lab 13 – Determination of active ingredient in TUMS (750 EXTRA!) –
a) Standardize the Base!
b) Perform the lab based on YOUR procedure!
1) Crush Tabs (2)
2) Add excess acid
3) Titrate Excess
4) Calculate the milligrams per tablet.
Period 4 –
2. Solutions concepts – this will help with part 1 of the Lab procedure
3. Lab 13 write – up
Today’s Lesson on the making of solutions:
12/2 – Wednesday – “D” Day – Homework:
1. You will be working on your lab 3 formal write-up in the shared google doc that I have sent you.
2. I have included the videos below to help with the write-up.
Here are the lab 13 write-up guidelines: DUE Friday at 11:59 pm
a) Background – A full page single typed. There is so much to write about. Do not forget to direct your discussion toward the Objective (which is to determine the milligrams of calcium carbonate in TUMS).
b) Detailed written procedure – There are 3 parts to your procedure.
( I will be scrutinizing your procedure and the conclusion)
The procedure has 3 parts!he-
1) Design of the lab.
2) Preparation of chemicals necessary to perform Back – Titration on 2 tabs of
750 mg TUMS (calcium carbonate = active ingredient)
a) KHP solution – used solid reagent
b) Excess acid solution – started with 1.o M HCl stock solution
c) Strong Base solution (for back titration) – started with solid reagent
3) Actual Steps taken to perform the lab in order to calculate the mg of active ingredient in 2 tabs of TUMs.
a) Standardization
b) tablet preparation
c) Titrations, etc.
c) calculations – Neatly presented – I have a video below that reviews how to complete the
calculations below. INCLUDE ALL REACTIONS!!!
I have posted 2 videos below that review this labs calculations:
d) data table (typed) INCLUDING SUBSCRIPTS!!!!!!!
Example: HC8H4O4– NOT HC8H4O4-
DESIGN YOUR DATA TABLE, BASED ON YOUR STEPS in the procedure that describes what you need to do to completely determine the milligrams of calcium carbonate in your TUMS tablet.
This will help you understand the Lab better and give you a head start to what we will do Monday when we Titrate the TUMs.
e) Results –
f) Conclusion – Please describe all errors and completely analyze you errors. It is a very accurate lab, all volumetric titrations are if the done precisely with standardized chemicals, However they are numerous errors to discuss and analyze.
Also try to discuss why your tablets milligrams of CaCO3 was not 750 mg in terms of the company that makes them (GSK).
g) Sources
This years review of calculations of the TUMS lab:
I have a review video for this lab FOR THE CALCULATIONS that was made last year with different concentrations: The process is the same. Notice I have mass of the 2 tablets which IS NOT NECESSARY in this lab. I would only need that if I was determining the percent of tablet that was the active ingredient.
Tum’s Back Titration Lab Setup – Monday’s Lesson – will help with part 1 of the procedure.
End of Wednesday ..
12/3 – Thursday “A” Day – period 2,3 (Lab) – I 2(A,C) 3(A) AP CHEMISTRY
–period 2,3 (Lab) – R 2(A,C) 3(A) REMOTE INSTRUCTION
-period 4 – I 3(C) 4(A,C) AP CHEMISTRY
-period 4 – R 3(C) 4(A,C) REMOTE INSTRUCTION
I will off Today..I am closing on my house!
The RED team and the Green team will be Remote today. Please move to the Remote instruction page.
Period 2/3, Period 4 :
1. Classwork – Work together in Lab groups to complete the following Form that will help understand your TUMs lab and help with the aspirin lab that we will be the next lab..
Please use the hardcopies of the form to help complete. This form is based on a design of a lab for another over the counter medication that will be very similar to the aspirin (BUT NOT THE SAME) that we will begin soon. Remember that you will be using a back titration as the active ingredient in Advil (Naproxen) is a weak (acid or base). Use your procedure in the TUMS lab to help solve this form which will compromise the calculations and steps needed to complete the quality control lab of the active ingredient of AleveTM .
The form will be on auto- reply and you have 3 replies individually. I will send out the handwritten when everyone has completed their responses from both classes. Some students may need to complete there final submissions as homework.
12/3 – Thursday “A” Day Homework– TUMS LAB DUE Tomorrow at 11:59 pm-
1. Complete the Aleve Form- 3 submissions per person.
Careful about your sig figs!
2. Complete the TUMS lab with a conclusion. Conclusions DO NOT INCLUDE ANOTHER PROCEDURE!!
Your conclusion will include the the explanation of the data written in your results sections. It will include error analysis. This is a very accurate lab but there are places in the procedure that error COULD of occurred. Please try to evaluate those possible instances AND HOW THEY explain YOUR results. How have the amount of errors in this experiment been controlled or limited? What was done to maximize accuracy? Do not just state this was an accurate lab. You need to explain why!
Everyone determined that the amount of active ingredient was UNDER the reported value (750 mg per tablet). What are the implications of this quality control experiment considering that our errors have been controlled or limited in our design of the experiment. What does your outcome as the quality control chemist mean for the consumer or the company.
3. Get the lab done! No homework this weekend!!
End of Thursday!
12/4 – Friday- “B” Day –period 2, – I 2(B,D) 3(D) AP CHEMISTRY
– period 2, – R 2(B,D) 3(D) REMOTE INSTRUCTION
-period 3,4 (LAB) – I 3(B) 4(B,D) AP CHEMISTRY
-period 3,4 (LAB) – R 3(B) 4(B,D) REMOTE INSTRUCTION
The Blue team and Orange team are remote today.
I am out again today. I thought I could come in today and teach you but I need to enroll my kids in their new school and close on my new house.
EXCELLENT JOB ON THE ALLEVE FORM for most of you. It was the same as the TUMS lab but in reverse and I like how many of you recognized that.
You all are incredible and I am honored work with you all!
Period 2, Period 3, 4
The plan is to complete the Tum’s Lab 13 –
In lieu of another fun form I am giving you class time to work on the TUM’s Lab.
Please use this time wisely!
Please make sure you have reviewed the requirements.
Make sure you have all 3 parts of your procedure.
Make sure you you have typed the calculations!
Presentation is utmost here!
12/4 – Friday- “B” Day – Homework –
NONE!
End of week 3!
NOT UPDATED BEYOND THIS POINT!
NOT UPDATED BELOW!
– period 2/3
You will determine the milligrams of aspirin by using 2 tablets of Bayer. Please look at the molecular structures of aspirin below to begin your lab design. Acetylsalicylic acid (aspirin) gets hydrolyzed into 2 components in water.
This is a slow reaction that can be increased by temperature and excess chemical (Le Chateliers principle).
Identification of organic acids can done by Table R in our Regents Chemistry reference tables:
1. Lab 12 – Determination of Aspirin in Bayer
Lab Assistant Ben!
period 4
1. Lab 12 – Determination of Aspirin in Bayer
Lab Assistant Ben!
Lab 12 – Aspirin Lab Test Requirements:
a: Using the Google Doc that is shared individually, start determining the procedure necessary to determine the amount of aspirin in a Bayer tablet.
USE THE TUMS LAB AS A GUIDE!!!
b: Understanding Lab 11 will help here. You need to figure out what chemicals you need and what their Molarities will need to be to successfully titrate aspirin.
You will need to complete preliminary calculations that will determine the theoretical amount of the other chemicals needed to perform the titration, in the same fashion as we did with Lab 11.
Look at your notes for Lab 11.
c: You will perform the titration and determine the milligrams of the active ingredient per tablet.
d: I will look over your procedure and preliminary calculations and give you the go ahead to
perform the Lab test.
e: In your Shared Lab group Doc, I expect
In this Lab Test I am require the following:
-
Title Page.
-
Objective.
-
materials
-
a detailed procedure
1) Design of lab – (arbitrary values decided on)
2) Calculations and steps to make certain solutions required in Lab.
3) Steps in the actual lab
-
Data Table
f) typed calculations page that report the milligrams of aspirin per
Tablet the final result. (DO NOT FORGET ANY CHEMICAL
REACTIONS!)
No Background, Results section or Conclusion necessary!
11/20 – Wednesday – Homework
1. Please begin your write-up of Lab 12 based on the requirements posted.
End of Wednesday…
11/21 – Thursday – period 2 –
Lets review the mechanism for the hydrolysis of aspirin:
1. Lab Test Aspirin –
period 3/4-
1. Lab Test Aspirin –
Connections:
The Balancing of complex Redox equations was a skill that was introduced this summer. We are revisiting redox again! It was introduced early in the year to splash you into the course, using voltaic cells (batteries) and electrolytic cells (electrolysis and electroplating). Now we will focus on redox reactions that are NOT part of a electrochemical cell and these complex reactions will make more sense when we balance them with the college method. This method still works for our simple half reactions that we saw in September but will provide more insight on their structure. Most of these complex redox reactions require an acidic or basic environment so it makes sense that I reintroduce them now, after we have studied acid/base concepts.
Most chemical reactions are redox in nature and I want To Do more stoichiometry Labs with redox in the analytical chemistry section of the course.
When you think about it most chemical reactions are either redox, acid/base, or precipitation reactions and through our work together we have studied all three since September.
Redox:
3 Mn+2 (aq) + CrO7-2 (aq) + 2H+(aq) —–> 3MnO2 (s) + 2Cr+3 (aq) + H2O (l)
precipitate
Acid Base:
NH3 (aq) + CO2 (aq) + H2O (l) —-> HCO3-1 (aq) + NH4+ (aq)
base acid base
Precipitation Reaction:
Ca+2 (aq) + CO3 -2 (aq) —–> CaCO3 (s)
precipitate
Now most reactions are one of these three types but as you can see above sometimes these reactions are a combination of each other. Notice that in the Redox reaction we have protons H+ (acid/base) and in the example above a precipitate ( MnO2 (s) ) is made. Redox reactions can also occur in Basic conditions as well.
Your homework will include balancing redox reactions in acidic and basic solutions. Why? Remember that protons produced by acids will pull electrons from chemical species that will spontaneously lose (oxidize) or AND hydroxides produced by bases will push its electrons onto chemical species that will spontaneously accept (reduce) them. The acid/base component of the complex redox equation that we will balance tonight is required to drive these reactions to completion. In order to use stoichiometry we need reactions to be driven forward till the limiting reactant runs out! We need to stay way from equilibrium!
ALSO the first 2 steps of the hydrolysis of aspirin is actually a redox reaction catalyzed by the presence of a the hydroxide ion!!!! Protons (H+) also catalyze these complex redox reactions and so we will learn (review from the summer) how to balance these advanced redox reactions in the presence of Acid or Base!!
11/21 – Thursday Homework:
1. Please read the connections above.
2. Please complete side 1 and 2 (questions 1 – 5) of the Redox 3 balancing redox equations.pdf worksheet and review with the key.
3. You will need to view the How to balance redox reaction in acid environment (College version) lecture for reactions 1 – 3 and How to balance redox reaction in basic environment for question 4.
Please use the key below to help review the homework, especially reaction 5.
Notes on how to balance complex reactions in acidic and basic solutions:
How to balance redox reaction in acid environment (College version) Lecture:
Questions 1 – 3 reviewed.
How to balance redox reaction in basic environment (College version) Lecture:
Question 4 reviewed.
End of Thursday…
11/22 – Friday – period 2/3
1. Lab 13 – Aspirin Test – Last period for data collection
Complete the write-up
period 4 –
1. Lab 13 – Aspirin Test – Last 2 period for data collection
11/22 – Friday – Homework. (Please read all 3 parts.)
1. Lab 11 – TUMS Lab should be completed for me to grade this weekend.
2. Lab 12 TEST- Please complete the Aspirin Lab – lab write-up requirements are posted under
Wednesday above. This will count as a test grade and a lab grade!
– For those groups that did not complete the data collection Friday, please email me with your work (screenshot) so that I can review. You will need to come in Monday in extra help to complete.
I understand that Lab 11 and Lab 12 are challenging to put all the concepts and moving parts together. Please do not feel that you are not getting it as fast as you should. All I care about is that you actually get it. This is not a sprint but a slow steady marathon (ran at a slower pace than Ashley)! Students that I have had in the past and that are currently in decent colleges struggled to get these labs. You will get it as they did and through the struggle you are building knowledge that will last beyond the spring.
Here is a email from past student from an Ok college that I received this fall:
First of all Adam was very gracious in complimenting me but HE DID THE WORK AND HE FOUGHT TO UNDERSTAND! All I did was lay out the game plan and provided help when necessary. SO keep FIGHTING and it will come!!!
Please see me with any questions!
We will build on the concepts of balancing complex redox reactions in acidic or basic environments with the following previously released AP Question from 2010. I gave this out over the summer in the redox module and most of you were blown away with it. It is amazing how for you all have come in very short time and I am sure that you will understand a lot more of this now.
3. Please complete the following released AP problem with we using the video below:
An older key but it will do the trick:
Stiochiometry 7 – 2010B.pdf video:
End of week 3!
Remote Instruction:
Week 3 – 11/30 – 12/4
11/30 – Monday – “B” Day –period 2, – I 2(B,D) 3(D) AP CHEMISTRY
– period 2, – R 2(B,D) 3(D) REMOTE INSTRUCTION
-period 3,4 (LAB) – I 3(B) 4(B,D) AP CHEMISTRY
-period 3,4 (LAB) – R 3(B) 4(B,D) REMOTE INSTRUCTION
The Blue team and the Orange team are remote today.
Zoom Stream Info:
Topic: AP Chemistry – 11.30 – Period 2,3,4
Time: Nov 30, 2020 08:00 AM Eastern Time (US and Canada)
Join Zoom Meeting
https://us02web.zoom.us/j/81162496313?pwd=YytEakdQZ2pzbVVKMDFIaTNDZS9OZz09
Meeting ID: 811 6249 6313
Passcode: AWM5VS
One tap mobile
+16465588656,,81162496313#,,,,,,0#,,480811# US (New York)
Period 2 , Period 3 :
1. Review Acid Base Test 2 (taken Last Tuesday) –
2. Tum’s Lab set-up notes. (This will be a formal lab).
Lab 13 – Determination of active ingredient in TUMS (750 EXTRA!) –
Note- taking – You will need these note to complete your procedure of lab 13.
Lab 13 – Determination of active ingredient in TUMS (750 EXTRA!) –
Period 4:
The Green team will be working on the Lab 13 – You may begin your homework.
Green team today:
a) Standardize the Base!
b) Perform the lab based on YOUR procedure!
1) Crush Tabs (2)
2) Add excess acid
3) Titrate Excess
4) Calculate the milligrams per tablet.
Please move to the week 3 page to view tonights homework.
12/1 – Tuesday – “C” Day – period 2, – I 2(A,C) 3(A) AP CHEMISTRY
– period 2, – R 2(A,C) 3(A) REMOTE INSTRUCTION
-period 3,4 (LAB) – I. 3(C) 4(A,C) AP CHEMISTRY
-period 3,4 (LAB) – R 3(C) 4(A,C) REMOTE INSTRUCTION
The Red team and the Green team are remote today.
Zoom Stream Info:
Topic: AP Chemistry – 12.01 – periods 2.3.4
Time: Dec 1, 2020 08:00 AM Eastern Time (US and Canada)
Join Zoom Meeting
https://us02web.zoom.us/j/84441183015?pwd=VHNJN3orUzNNM3k5Z21jeXVpdFNhQT09
Meeting ID: 844 4118 3015
Passcode: i924DD
Period 2:
Please view the discussion on the standardization of the NaOH with me in class for first 5 – 10 minutes.
We will run the lab tomorrow!
Notes on the lab:
Standardization of the Strong base in this back titration of TUMS.
In this analysis of the “active ingredient” of Tums ( CaCO3 ) we will need to use a strong base to titrate the excess HCl that was used to drive the reaction to completion:
Net Ion: 2H+ (aq) + CaCO3 (s) —> CO2 (g) + H2O (l) + Ca+2
Excess
The excess Strong Acid will drive the reaction to completion due to Le Chateliers Principle. It also important to to have excess Strong Acid to react with all the CaCO3 that will be mixed and “hidden” with the binder, coloring, flavor, and etc. That is why it is important to crush the tablets (tabs!) with a mortar and pestle in order to expose all of the salt, CaCO3 to the acid.
Now after we add the excess acid we will have to Titrate this excess acid with a Strong Base. This lab produces incredibly accurate results ONLY IF OUR SOLUTIONS that we use ARE ACCURATE. We are adding 0.04 moles of protons from the 100.0 ml of a 0.4 M HCl solution. Because we are adding about 0.01 moles of extra protons from the strong acid we need to titrate the excess protons with a strong base AND that solution needs to verified or STANDARDIZED.
I made a 0.5 M NaOH solution. I was very careful to make this solution BUT because strong Bases are very reactive that solution is definitely LOWER in concentration as the hydroxide reacts with the CO2 (Lewis Acid) in the air. I used 20 grams of solid NaOH (.5 mole) dissolved in a 1 liter of solution to make a 0.50 M NaOH solution
BUT not all of the solid is NaOH as CO2 from the air will cause the NaOH to become Na2CO3. This also happens in solution. Strong bases are carbon dioxide scrubbers that are used to remove it from space capsules.
2NaOH(s) + CO2 (g) —–> Na2CO3 + H2O
Also NaOH is deliquescent which means it can absorb water from the air and start dissolving itself. This would add weight to the Base and dilute is quantity.
Because NaOH has these issues we need to verified or STANDARDIZE it with a weak acid that is not reactive and does not have these issues. A perfect solution to this (no pun intended!) is using KHP. Potassium Hydrogen Phalate.
KHP, (KHC8H4O4) is excellent to standardize a Strong Base with because it
1. Weak Acid – thus does not react unless forced to by a Strong Base
2. Is a solid – we eliminate volume errors when making this solution
3. It has a large molecular mass (204 g/mol) – measurement errors with a large
molecular mass will not lead
to large mole errors.
Net Ion: HC8H4O4– + OH– —-> C8H4O4– 2 + H2O
You will find from this standardization that my solution of 0.50 M NaOH is less but we need to know its exact value to proceed with the lab.
Lab 13 – Determination of active ingredient in TUMS (750 EXTRA!) –
a) Standardize the Base!
b) Perform the lab based on YOUR procedure!
1) Crush Tabs (2)
2) Add excess acid
3) Titrate Excess
4) Calculate the milligrams per tablet.
Period 3,4 (LAB) – you guys did the lab yesterday but it might be helpful to listed to beginning of the class to better understand what you did in lab yesterday.
1. Notes on Lab – Standardization –
Once you listen to the intro you can start writing up the lab 13. I will send a google doc today sometime to begin your write-up of the lab. That is you homework and the guidelines are posted in the week 3 page under homework.
2. Run the lab – The Orange team will run the lab today
Lab 13 – Determination of active ingredient in TUMS (750 EXTRA!) –
a) Standardize the Base!
b) Perform the lab based on YOUR procedure!
1) Crush Tabs (2)
2) Add excess acid
3) Titrate Excess
4) Calculate the milligrams per tablet.
FULL REMOTE STUDENTS I WILL LIVE STREAM A LAB GROUP SO YOU CAN GRAB THE THE DATA.
Remote Students Data – Titration curve of the back titration.
FULL REMOTE STUDENTS – video of lab:
12/2 – Wednesday- “D” Day – period 2,3 (Lab) – I 2(B,D) 3(D) AP CHEMISTRY
– period 2,3 (Lab) – R 2(B,D) 3(D) REMOTE INSTRUCTION
-period 4 – I 3(B) 4(B,D) AP CHEMISTRY
-period 4 – R 3(B) 4(B,D) REMOTE INSTRUCTION
The Blue teams and the Orange Team are remote today.
Zoom Stream Info:
Topic: AP Chemistry – 12.02 – periods 2,3,4
Time: Dec 2, 2020 08:00 AM Eastern Time (US and Canada)
Join Zoom Meeting
https://us02web.zoom.us/j/84777957891?pwd=elJkT2l4dnhVVGp1YUVhVXcwQWZhZz09
Meeting ID: 847 7795 7891
Passcode: 7sWF4j
One tap mobile
+16465588656,,84777957891#,,,,,,0#,,412002# US (New York)
Period 2,3 –
1. Review Monday’s form –
2. Solutions concepts – this will help with part 1 of the Lab procedure
3. Run the Lab – The Blue Team can work on the lab write-up
while the RED team completes the Lab
Lab 13 – Determination of active ingredient in TUMS (750 EXTRA!) –
a) Standardize the Base!
b) Perform the lab based on YOUR procedure!
1) Crush Tabs (2)
2) Add excess acid
3) Titrate Excess
4) Calculate the milligrams per tablet.
Period 4 –
2. Solutions concepts – this will help with part 1 of the Lab procedure
3. Lab 13 write – up
12/3 – Thursday “A” Day – period 2,3 (Lab) – I 2(A,C) 3(A) AP CHEMISTRY
–period 2,3 (Lab) – R 2(A,C) 3(A) REMOTE INSTRUCTION
-period 4 – I 3(C) 4(A,C) AP CHEMISTRY
-period 4 – R 3(C) 4(A,C) REMOTE INSTRUCTION
I will off Today..I am closing on my house!
The RED team and the Green team will be Remote today.
Period 2/3, Period 4 :
1. Classwork – Work together in Lab groups to complete the following Form that will help understand your TUMs lab and help with the aspirin lab that we will be the next lab..
Please use the hardcopies of the form to help complete. This form is based on a design of a lab for another over the counter medication that will be very similar to the aspirin (BUT NOT THE SAME) that we will begin soon. Remember that you will be using a back titration as the active ingredient in Advil (Naproxen) is a weak (acid or base). Use your procedure in the TUMS lab to help solve this form which will compromise the calculations and steps needed to complete the quality control lab of the active ingredient of AleveTM .
The form will be on auto- reply and you have 3 replies individually. I will send out the handwritten when everyone has completed their responses from both classes.
Quality Control Aleve Form.pdf
Quality Control of Aleve Form:
12/4 – Friday- “B” Day –period 2, – I 2(B,D) 3(D) AP CHEMISTRY
– period 2, – R 2(B,D) 3(D) REMOTE INSTRUCTION
-period 3,4 (LAB) – I 3(B) 4(B,D) AP CHEMISTRY
-period 3,4 (LAB) – R 3(B) 4(B,D) REMOTE INSTRUCTION
The Blue team and Orange team are remote today.
I am out again today. I thought I could come in today and teach you but I need to enroll my kids in their new school and close on my new house.
EXCELLENT JOB ON THE ALLEVE FORM for most of you. It was the same as the TUMS lab but in reverse and I like how many of you recognized that.
You all are incredible and I am honored work with you all!
Period 2, Period 3, 4
The plan is to complete the Tum’s Lab 13 –
In lieu of another fun form I am giving you class time to work on the TUM’s Lab.
Please use this time wisely!
Please make sure you have reviewed the requirements.
Make sure you have all 3 parts of your procedure.
Make sure you you have typed the calculations!
Presentation is utmost here!