This essay focuses on a chemistry practice test / quiz and need support. The assessment is only one hour long. I will be uploading screenshots of the questions
to help me learn.
Hi, I have an organic chemistry assessment tomorrow (05/19/2021) at 11:50 am PST. The assessment is only one hour long. I will be uploading screenshots of the questions to you during the time frame. Topics being covered on the assessment are:
– Aldehydes and Ketones—Nucleophilic Addition
– Carboxylic Acids and Their Derivatives—Nucleophilic Acyl Substitution
– Substitution Reactions of Carbonyl Compounds at the a-Carbon )
of aldehydes and ketones, we need to look back and remind ourselves
of what the bonding picture looks like in a carbonyl. Carbonyl carbons are sp2 hybridized, with the three sp2 orbitals forming three sigma bonds by overlapping with orbitals from the R groups (carbons or hydrogens) and an sp2 hybrid orbital from oxygen. Due to the sp2 orbitals, these three bonds adopt trigonal planar geometry seen in carbonyls. The carbonyl carbon’s remaining unhybridized 2p orbital is perpendicular to this plane, and forms a ‘side-by-side’ pi bond by overlapping with a 2p orbital from the carbonyl oxygen.
since oxygen is more electronegative than carbon. The electron density is higher on the oxygen side of the bond and lower on the carbon side. Recall that bond polarity can be depict with a dipole arrow. (Pointing toward the more electronegative atom). This is by showing the oxygen as holding a partial negative charge and the carbonyl carbon. with a partial positive charge. A third way to illustrate the carbon-oxygen
dipole is to consider the two main resonance contributors of a carbonyl group: the major form, which is what you typically see drawn in Lewis structures, and a minor but very important contributor in which both electrons in the pi bond are localize on the oxygen, giving it a full negative charge. The latter depiction shows the carbon with an empty 2p orbital and a full positive charge.