IR Spectroscopy: Some Simple Practice Problems

November 29, 2016

By itself, Infrared (IR) spectroscopy isn’t a great technique for solving the structure of an unknown molecule. However, we’ve seen that IR spectroscopy can a great technique for identifying certain functi…

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Infrared Spectroscopy: A Quick Primer On Interpreting Spectra

Infrared Spectroscopy: A Quick Primer On Interpreting Spectra

November 23, 2016

How To Interpret IR Spectra In 1 Minute Or Less: The 2 Most Important Things To Look For [Tongue and Sword] Last post, we briefly introduced the concept of bond vibrations, and we saw that we can think of covalent b…

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Organic Chemistry and the New MCAT

Organic Chemistry and the New MCAT

November 16, 2016

Organic Chemistry and the MCAT, by Leah Fisch Note from James: This is a guest post by Leah Fisch of Leah4Sci.com , an online resource for learning organic chemistry, MCAT preparation, and other science topics . Th…

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Bond Vibrations, IR Spectroscopy, and the “Ball and Spring” Model

Bond Vibrations, IR Spectroscopy, and the “Ball and Spring” Model

November 11, 2016

In This Post  Why do UV spectra have such broad peaks? The “stadium” analogy. Introduction to vibrational energy levels. Visualizing different vibrational energy levels A useful analogy: the “ball a…

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Alkene Nomenclature: Cis and Trans and E and Z

Alkene Nomenclature: Cis and Trans and E and Z

November 3, 2016

This post was co-authored with Matt Pierce of Organic Chemistry Solutions.  Ask Matt about scheduling an online tutoring session here. Earlier on our MOC series on cycloalkanes, we saw that a key feature of small …

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Introduction to Assigning (R) and (S): The Cahn-Ingold-Prelog Rules

Introduction to Assigning (R) and (S): The Cahn-Ingold-Prelog Rules

October 20, 2016

This post was co-authored by Matt Pierce of Organic Chemistry Solutions.  Ask Matt about scheduling an online tutoring session here. Previously on MOC we’ve described enantiomers: molecules that are non-superim…

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UV-Vis Spectroscopy: Some Practice Questions

UV-Vis Spectroscopy: Some Practice Questions

September 27, 2016

In the past few posts we’ve covered some of the key points of UV-Vis spectroscopy. Now comes the key question: how do we apply it? How can it be useful to us, especially in determining the structure of unknown c…

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UV-Vis Spectroscopy: Absorbance of Carbonyls

UV-Vis Spectroscopy: Absorbance of Carbonyls

September 26, 2016

In our last post we showed that molecules with C-C pi (π) bonds absorb light in the UV-visible region, which promotes electrons from (bonding) π orbitals to (anti bonding) π* orbitals. We saw that the energy requ…

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Introduction To UV-Vis Spectroscopy

September 16, 2016

In today’s post we’ll discuss why most molecules are colourless, introduce the useful technique of UV-visible spectroscopy, and finally explain why molecules like chlorophyll and β-carotene are coloured.…

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How Bleach Works: Understanding Colors From Nature

September 8, 2016

Why are tomatoes red? Why are carrots orange? Why are egg yolks yellow?   And… why is Vulcan blood green? OK, I’m not going to touch that last one, but as for the first three: great question. There are…

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