@Emma Nasipova problem being that u look before, but just cant find anything and then 1 week later yt starts to recommend the best videos about the stuff u were looking for
The primary purpose of the video is to determine those values through multiple different methods. Each of those 4 values are all determined from the graphs made from the data in the colored columns prior (columns B-N). The video will walk through each of these. - Eyeball was from the titration curve (raw data) and looking for the rapid change in pH (about 14 minutes in) - The first derivative value was based on the peak in the first derivative plot (about 22 minutes in) - The second derivative value was based on the crossover from positive to negative in the second derivative plot (about 27 minutes in) - The gran plot value is based on the onset of the curve (when it changes from sloped to flat) which is at the x-intercept (about 37 minutes in)
Hi! I was wandering if you could upload the excel sheet you used in the clip, I would be very thankful if you could do that. I'm doing a automated titration project, and having this sheet for analysing the data would be wonderful. Thanks!
Are you referring to the second derivative plot? There are one of two reasons that this might occur: (1) you have a polyprotic acid (or base), such as H2SO4 which can undergo two deprotonations to first form HSO4^- and then SO4^2-. Each of the deprotonations will result in a equivalence point. or (2) the data you collected has too large of intervals (or fluctuations with pH measurements by going to fast) between data points, so you might see a few crossovers around the equivalence point. If that is the case, you can use the first derivative maximum or just eyeball it via main plot.
why do some people skip the first entry of first derivative and the first 2 of second instead of skipping at the end? I did it the way you did and got different results than my collegue who did it by skipping at the begining.
The derivative is the rate of change between two points, so you will always need to "sacrifice" an entry because you need n+1 entries. You can't get a derivative with just one point. The difference between choosing the first or last should be minimal, typically only 0.5 mL or less if you collect good data points around the equivalence point. In reality, your eq pt from this approach has uncertainty scaling to the difference between two entities, so it is likely both you and colleague are within error/uncertainty of each other (assuming math was done correctly)
I am like a foolish 傻逼。I finally found out that the video is so helpful after turning in the assignment....
@Emma Nasipova problem being that u look before, but just cant find anything and then 1 week later yt starts to recommend the best videos about the stuff u were looking for
Thank you!
very informative! great! tnx
this was really helpful, thanks.
This was very helpful, thanks!
How dou you calculate the V eq on the table constant and calculations?
The primary purpose of the video is to determine those values through multiple different methods. Each of those 4 values are all determined from the graphs made from the data in the colored columns prior (columns B-N). The video will walk through each of these.
- Eyeball was from the titration curve (raw data) and looking for the rapid change in pH (about 14 minutes in)
- The first derivative value was based on the peak in the first derivative plot (about 22 minutes in)
- The second derivative value was based on the crossover from positive to negative in the second derivative plot (about 27 minutes in)
- The gran plot value is based on the onset of the curve (when it changes from sloped to flat) which is at the x-intercept (about 37 minutes in)
Hi! I was wandering if you could upload the excel sheet you used in the clip, I would be very thankful if you could do that. I'm doing a automated titration project, and having this sheet for analysing the data would be wonderful. Thanks!
Very helpful thanks a lot ! :D
Thanks a lot, good done
great video, which explains everything about graphs of the titration...thanks
Thank you so much for this sir, but may I ask? what if there are multiple curve that intersects the x-axis?
Are you referring to the second derivative plot? There are one of two reasons that this might occur: (1) you have a polyprotic acid (or base), such as H2SO4 which can undergo two deprotonations to first form HSO4^- and then SO4^2-. Each of the deprotonations will result in a equivalence point. or (2) the data you collected has too large of intervals (or fluctuations with pH measurements by going to fast) between data points, so you might see a few crossovers around the equivalence point. If that is the case, you can use the first derivative maximum or just eyeball it via main plot.
@@jeromyrech327 Thank you so much Sir! the information really help me in my chem lab report! Hope to learn more from you!
why do some people skip the first entry of first derivative and the first 2 of second instead of skipping at the end? I did it the way you did and got different results than my collegue who did it by skipping at the begining.
The derivative is the rate of change between two points, so you will always need to "sacrifice" an entry because you need n+1 entries. You can't get a derivative with just one point. The difference between choosing the first or last should be minimal, typically only 0.5 mL or less if you collect good data points around the equivalence point. In reality, your eq pt from this approach has uncertainty scaling to the difference between two entities, so it is likely both you and colleague are within error/uncertainty of each other (assuming math was done correctly)
Hey man great video to explain the analysis but watch the "uhh" and the "uhm" you say those a lot. Makes it a bit hard to focus.
No it doesn't.