Chemguides

Can you predict the relative concentrations of aqueous species within acid-base equilibria? 💦🧪

Learn these skills and test your understanding via the Gen Chem & Analytical Course Guide & Videos .com! 👩‍🔬📚

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Victoria Bowser is a 3rd year dental student at Boston University! 🦷

She studied with David in preparation for her undergraduate chemistry courses and the DAT. 📚

Victoria earned a perfect 31 on the organic chemistry section of the DAT. 💯

Congrats, Victoria! Your dedication and work ethic have driven immense success in chemistry & dentistry!📝

“Hello, I am Victoria Bowser. I graduated from the University of Alabama with a chemistry degree, and I am currently a third year dental student at Boston University. I hold David in the highest regards because of immense help he provided through all of my chemistry classes.

David was my go-to resource throughout Organic Chemistry I and II and the associated labs. He was a huge help going over my lab reports with me before I would start writing them. He would explain the concepts behind all the labs and give me a true foundation and understanding of what I was doing and the questions I needed to answer for each report.

David is incredibly reliable, and he always made time for extra review sessions and to explain concepts and questions that I really had a hard time understanding. David’s ability to explain complex concepts with such clarity and make them feel simple is what makes him such a fantastic tutor. Without David,I truly believe I would have never gotten all A’s in my chemistry classes and labs nor would I have gotten a perfect 31 on the organic chemistry section of the DAT.”

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Can you determine the number of delocalizable electrons in a given organic compound? 🧑‍🔬👩‍🔬

Leave your answer in the comments below!📝

Swipe➡️ for the solution!

Delocalized electrons are those that are housed in pi orbitals that form from the conjugative overlap of contiguous & parallel p orbitals. We explain delocalization by drawing resonance structures‼️

Delocalized electron pairs include those that are depicted as pi bonds or perhaps nonbonding (lone) pairs in a given resonance structure.🔄

Can you draw additional resonance contributors for the compound above? 🔍

Learn more regarding delocalization and electronics via the ORGO I-II Video Series!
https://chemguides.com/videos/

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Guess what? Another CHEMGUIDES success story!

Cole Davis excelled in Organic Chemistry 🧪 under David’s guidance.

Cole then took his talents to 🩺MED SCHOOL⚕️ in St. Louis. Congrats, ‼️

“Hi! I’m Cole Davis, and I’m currently a first-year medical student at Washington University in St. Louis.I wanted to shout out David for getting me through Organic Chemistry I and II at Duke. He was able to cater specifically to how the course was taught at Duke, especially in learning and understanding electron flow in reaction mechanisms, which is something I really struggled with before meeting him. He also tutored me in a group with friends, which was a good way of making sure that I was on par with my classmates. David’s style is straightforward and tailored, which worked for me. He didn’t just cover the material; he made sure I really got it. It’s paying off big time in med school now. I highly recommend getting started with him if you are even slightly considering a tutor for your coursework!”

Do you want to succeed in your chemistry course and build a competitive record for medical, dental, or pharmacy school admissions? SIGN UP TODAY .com! 📚💯

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Can you determine the predominant (lowest energy) protonation state of bufotenin (🐸 venom) at aqueous pH 7.00? Swipe ➡️ to learn more!

“I worked with David during my nontraditional undergraduate studies at Columbia University. Before Columbia, I spent ten years building a career and a business and then decided to return to school to pursue medicine. Chemistry presented one of the most substantial academic hurdles after being out of school for so long.

Unfortunately, I didn’t meet David until I had already struggled through general chemistry and organic chemistry I. During Orgo I, a TA of mine continually recommended widening my view of the subject and understanding concepts and properties over specific mechanisms. While I understood this idea on an intellectual level, I found it difficult to practically apply it without additional guidance.

David’s notes and guides allowed me to begin practicing this method of learning without even realizing I was doing it. After a couple of months of working independently and meeting with David for challenging topics, I had a new working knowledge and intuition for chemistry that had never been possible before. I took this foundational knowledge into biochemistry and inorganic chemistry and excelled in both courses.

Most meaningfully, I achieved a 96th percentile score on the MCAT chem/phys section thanks in part to employing David’s approach to other subjects. After having a rocky start, I’ve been asked to TA for inorganic chemistry, which is a true testament to what is possible with dedication and a mentor like David. I highly recommend David’s videos, course guides, and his group or one-on-one tutoring!”

-LH, Columbia University, Biological Sciences

BIOCHEMISTRY STUDENTS‼️
Can you distinguish between D & L amino acids? 👩‍🔬
Leave your answer in the comments!
SWIPE ➡️ for the solution.

Of the 20 common naturally occurring amino acids, 19 are chiral. 🧬
Glycine is achiral as it lacks an asymmetric center.

All 19 chiral amino acids are “L” in configuration.
“L” describes the 3D configuration of functional groups with respect to the asymmetric alpha carbon.
You can think of “L” as being “Left-Handed” but in reality, this 3D configuration is based upon L-glyceraldehyde.🍬

D & L do not always correspond to R & S absolute configurations, respectively.
18/19 L amino acids are S in absolute configuration at the alpha carbon. 🔄
1/19, L-cysteine has the R absolute configuration since the 2nd highest priority is the side chain, -CH2SH. 🔁

Do you recall how to assign R & S? Learn to simplify the complexity of stereochemistry at chemguides.com! Subscribe to the video series today to improve your exam performance! 📚

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“My name is Hannah and I am a career changer currently applying to medical school. As someone who had not taken chemistry since freshman year of high school over 10 years ago, I was nervous for the intensive courses at my post bac program. David is a huge part of the reason I did well in organic chemistry and biochemistry. I have worked with other tutors before and have never met someone who is as professional, tech savvy, and helpful as David. He makes the most of every session and helps ensure you are prepared beyond your meetings with his free and subscription videos. Both the knowledge and confidence he gave me to tackle chemistry are invaluable and I would recommend him to anyone.”
-Hannah Silverman, UVA Pre-Med Post Baccalaureate

ANALYTICAL, ORGANIC & BIOCHEMISTRY STUDENTS!! 🧬🩺

Which structure correctly depicts the predominant form of lysine at aqueous pH 9.70?💧

Leave your answer in the comments! Swipe➡️ for the solution!💯

Do you want to sharpen your acid-base skills?📝

Sign up today for the COURSE GUIDES 🔓📚.com!

5000+ Exam-Like Practice Exercises & Illustrated Solutions🔍

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