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- 578 887
Robyn Goacher
United States
เข้าร่วมเมื่อ 9 ต.ค. 2011
Polyprotic Acid-Base Part 4: Titrations & Indicators
This lesson follows what is present in the sample flask at each point in the titration of a polyprotic weak acid with a strong base, emphasizing what mathematical approach you should take to calculate pH (the math is in 'part 3' of this polyprotic acid-base video series).
The detection of the endpoint is also discussed - comparing acid-base indicators with pH meters (with first derivative, second derivative and Gran plots).
The detection of the endpoint is also discussed - comparing acid-base indicators with pH meters (with first derivative, second derivative and Gran plots).
มุมมอง: 7 165
วีดีโอ
Polyprotic Acid-Base Part 2: Buffers
มุมมอง 5K3 ปีที่แล้ว
This lesson discusses how to calculate the pH of a buffer made from polyprotic acid-base compounds, and how to determine how much strong acid to make a buffer of a certain pH from a polyprotic weak base. These examples demonstrate how to choose the correct Henderson-Hasselbalch equation and how to solve buffer-involved reactions using an ICE chart.
Polyprotic Acid-Base Part 3: Calculation pH and Concentrations
มุมมอง 3.3K3 ปีที่แล้ว
This lesson explains how to calculate the pH and the concentrations of the pure polyprotic weak acid, intermediate forms, and pure polyprotic weak base when a solution is made from any one of these forms.
Polyprotic Acid-Base Part 1: Dominant Species
มุมมอง 4.2K3 ปีที่แล้ว
This lesson introduces polyprotic acids and bases and explains how to identify the dominant species at a given pH for monoprotic, diprotic, and triprotic acid series.
Christmas Lights display North Tonawanda NY 2019 (song 2)
มุมมอง 6844 ปีที่แล้ว
Christmas Lights display North Tonawanda NY 2019 (song 2)
Christmas Lights display North Tonawanda NY 2019 (song 1)
มุมมอง 1.1K4 ปีที่แล้ว
Christmas Lights display North Tonawanda NY 2019 (song 1)
Activities and Systematic Treatment of Equilibria
มุมมอง 9K6 ปีที่แล้ว
Activities and Systematic Treatment of Equilibria
Monoprotic Acid Base Equilibrium-Acid vs Water, Buffers
มุมมอง 4.9K6 ปีที่แล้ว
Monoprotic Acid Base Equilibrium-Acid vs Water, Buffers
chromatography follow up video
มุมมอง 8K6 ปีที่แล้ว
This is really just a continued lecture for my fall 2017 class. This video is not the best for public consumption (please watch my other chromatography lectures for a more linear-contextually useful explanation).
Multiple Standard Additions
มุมมอง 5K6 ปีที่แล้ว
This video goes through the planning and calculations of both variable volume and constant volume multiple standard additions approaches.
Comparing Concentration Standardization Methods
มุมมอง 10K6 ปีที่แล้ว
Comparing Concentration Standardization Methods
Spike Recoveries
มุมมอง 32K6 ปีที่แล้ว
Understanding what a spike recovery is, why to use it, how to choose between the two types, example calculations, and how to plan to do each kind of spike recovery in lab.
Spectroscopy Basics (longer)
มุมมอง 6K6 ปีที่แล้ว
More details on the basics of spectroscopy, focusing on the fundamental principles of the energy of light and how this interacts with atomic and molecular orbitals. Also includes explanation of chromophores, Beer's law, and key steps to properly making a spectrometry measurement.
Calibration Curves, Blanks, and Method Verification Terminology
มุมมอง 50K6 ปีที่แล้ว
Calibration Curves, Blanks, and Method Verification Terminology
Statistics Overview and Significance Testing
มุมมอง 8787 ปีที่แล้ว
Statistics Overview and Significance Testing
Polyprotic Acids and Bases (with Titrations)
มุมมอง 2.4K8 ปีที่แล้ว
Polyprotic Acids and Bases (with Titrations)
We love you
nice explanation, very helpful, but what if the unknown matrix signal is negative, suppose -0.345 AU?
It's really hard to believe that such great teachers exist in this broken education system. Ma'am, you are just awesome! Thank you for making these videos.
Thank you - I appreciate the praise. Sadly, the broken education system drove me out of it and I work in industry now. But I did enjoy the teaching part of teaching!
@@robyngoacher8521 You hang in there, Ma’am!
This was perfect. Thank you so much.
Hi, can I replace the concentration with the weight fraction?
Book reference please
Amazing explanation, thank you very much
Thank you so much
thank u so much
Can you add in Kw with the equation? Do I just need to add a 1/[H+]kw or something like in the charlot equation
Amazing Video!!!
Thank you so much! The formulae always scare me, but this was a lot easier to understand than my lectures. I finally get it! (My exam is tomorrow lol)
You are the best teacher😊
Thank you so much for very helpful video! I have one question. If I got 90% recovery for my protocol. Then, I got 10 ug/kg for my sample. Do I have to calculate back to 100% because of my protocol can detect only 90%.
You are genius
I think F value is wrong 😅 it's 1.25
Good
Thank you for the great video. While we are taking the dilution into account, won't we also consider the reduction in sample volume caused due to signal measurement? The V0 becomes a variable then..?
Your question relates to whether "variable volume" or "constant volume" standard additions are done. In variable volume standard additions, the exact same solution is measured, spiked with standard, measured again, spiked with more standard and measured again (and so on). In that kind of standard addition, you cannot use a measurement technique that consumes sample. If you will consume the sample during measurement (even if that means losses due to transferring into and out of a cuvette for spectroscopy), then you should use constant volume standard additions. In constant volume standard additions, the V0 is the same for all flasks and you are able to do the math without needing to account for change in V0. So, no, the V0 does not become a variable. I hope that helps.
Nice
Wonderful presentation...very informative. Thank you
Is this is how we calculate GC yield?
The volume is to low !!. Re do the Video. Thank you.
I think this formula you wrote incorrect. K= concentration/ Absorbance
great work mam thank you so much
Which text book are you using? I need to calculate an overlap integral for my BSc project. Thanks in advance.
The book was Quantitative Chemical Analysis by Harris. Best of luck to you!
@@robyngoacher8521 thank you. I really enjoyed your video 😊
thank you
Great, prof! New subs here
Thanks for this awesome video. Are blank solutions also known as control solutions?
The wording isn't always clear when something is called a control. In biological and medical experiments in particular, the control is something that doesn't have the affect-so no treatment or no drug. In that way, the control is kind of like a blank. But in analytical chemistry, the blank does not contain the analyte while control solutions contain the analyte in a known quantity. Therefore the blank provides information about the background and the control is used for checking if your method produces the right concentration of analyte. I hope that makes sense and answers your question.
@@robyngoacher8521 thanks mom. Is very clear now
Is there a difference between matrix effect and recovery percent, or are they one in the same?
Matrix effect is the concept that analytes will respond differently in different systems. Spike recovery is the most common way to measure whether a matrix effect is present. If the spike recovery is close to 100%, then you can conclude that the analyte behaves the same in your sample (which is spiked) as it did in the set of simpler solutions used for calibration. I hope that helps.
just what i needed, thanks
th-cam.com/channels/U1Tb8wdJDRJTV37Qqm3RLA.html
In some cases the spike sample is about 50 to 100 times the known concentration. I analyze Cocoa samples I was at first having a problem with spike but following the 50 to 100 times I got my results
you.talk.so.fast
Many thanks
❤️💯 the way you just saved me from studying this topic all over again from scratch 😃
would be able to help me clear my doubts that what factors decide the type of calibration either linear or logit calibration? and also what determines number of standards required for an assay calibration?
IS murexide Triprotic?
Thank you so much
You saved me. Thank you so much.
Oh, dear, this is what I urgently need to learn. Thank you very much
You are so cute！！
can you speak louder i cant hear you
Great lecture. thanks. can you please post the links of other 3 related videos here
Hi Robyn would you refer to a source to help with determining pre validation parameters in a lab?
Thank you! What book can you recommend to read about general principles of chromatography?
Any edition of Harris's Quantitative Chemical Analysis provides a good basis.
chem.libretexts.org/Bookshelves/Analytical_Chemistry/Supplemental_Modules_(Analytical_Chemistry)/Analytical_Sciences_Digital_Library/JASDL/Courseware/Teaching_Instrumental_Analysis_without_a_Textbook is also a great free online resource
@@robyngoacher8521 Fantastic lecture. Please take lecture on Preparative HPLC and spectroscopy.
Thank you - very helpful!
Wonderful video. Which textbook would you recommend for pharmacy undergraduate students
She is pretty 😃
Improve audio quality
Thank you for this wonderful presentation:)