Solving Serial Dilutions | MCAT Content

In this video we will go over how to solve regular and serial dilution problems. While I will introduce the equations that underlie the approach to serial dilution problems we won’t be relying on them since I find it easier to use a simple 3-step approach to solving these types of questions rather than setting up a series of dilution equations.
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00:00 - Introduction
00:17 - MiVi=MfVf
00:44 - Single Dilutions
01:39 - Setting Up Dilution Problems
02:58 - How To Solve Alternative Setups
05:14 - Applying Single Dilution Concepts to Serial Dilutions
08:11 - Serial Dilution Example Problem

[@riyaa.8421]

your videos are so helpful to me and it's honestly encouraged me to keep studying without giving up. I wish there were more videos I can depend on haha, but I'm so grateful for all the help

[@kajalpatel2150]

your mcat content is great ! so high quality and really help learn the content in context of how its asked! really appreciate these videos :)

[@EightfoldMCAT]

Thank you!!! Glad you are finding the videos helpful.

[@banaa2848]

Binge watching all your vids before my mcat, these are so helpful ty! Do you plan to cover any orgo topics? Or any tips on what the main orgo topics to focus on in time crunch :)

[@EightfoldMCAT]

Glad you are finding the videos helpful! Orgo is kinda weird on the MCAT in the sense that it isn’t that similar to what you are expected to know in college. While I will eventually make videos on this topic it is probably going to be a while since I have a video backlog at present. The most important things to know for the MCAT are the lab techniques, nomenclature and stereochemistry, functional groups and their properties (polarity, general types of reactions they undergo, naming, etc.), and lastly being able to trace out how reactions are occurring on the basis of a given reaction scheme (this skill is way more important than knowing all of the various reactions and arrow pushing mechanisms are practically useless on the MCAT.)

[@cardiocosmos]

Thank you so much!!

[@EightfoldMCAT]

Your welcome! Glad the video was helpful.

[@user-ey4yj2ds1x]

you're amazing!

[@cameronmciver7588]

Great video! Thanks for sharing. I see you're experimenting with different speaking paces. I tip I learned to speak clearly is to practice stretching words out in the shower/practice venue of your choice. Clear speaking isn't just about elongating the pauses / avoiding slurring, its about elongating your vocalizations too!

[@EightfoldMCAT]

Thanks for the tip I will definitely give that a try. I have gotten some feedback that I talk too fast. I script all of the videos to make sure that I don’t go off topic and hit all of the points I want to, but since I am essentially just reading what I have already written I don’t have to think and talk at the same time so I can speed through the material too quickly at times. I am experimenting to try and figure out the right speed which is a lot harder than I thought it would be.

[@hookem3768]

At 7:00 wouldn't the first dilution factor be 2:5 (two parts original concentration to 5 parts total volume) according to your earlier definition? And the second dilution factor would be .01:40.01?

[@hookem3768]

I think I see why. In your earlier examples you showed three flasks of different volume but only focused on the one of known concentration and volume, and the one which has the new mixture. At the 7:00 mark the dilution factor is 2:3 (instead of 2:5) because you did not show the 1 mL solution you must have mixed the initial 2mL one with. The same logic describes the second dilution factor.
Did I figure it out?

[@EightfoldMCAT]

In the dilution you are referencing the final volumes of the solutions were given rather than the amount that was added. So in the first dilution you started with 2 mL and it was diluted to a total volume of 3 mL so it would stay as a 2:3 dilution in the second dilution the same thing occurred. In the second dilution it is the same. The final volume of 40 mL was given so it would also be a 0.01 : 40 dilution. The difference between this dilution and the last one is that in the previous ones the final volume wasn’t given and had to be calculated based on the amount of solution that was added. The AAMC can ask dilutions both ways: giving you the amount added or the final amount, just make sure you are careful about identifying which type of information is given and always find the final solution volume since that is the one that counts!