Chemistry Test Organic Chemistry 2

Question 1

Which reagent is used to convert a primary alcohol to an aldehyde without over-oxidizing to a carboxylic acid?

Accepted Answer

PCC (pyridinium chlorochromate)

Answer

PCC is a mild oxidizing agent that stops oxidation at the aldehyde stage for primary alcohols.

Question 2

What type of isomers have the same molecular formula and connectivity but differ in the spatial arrangement of atoms that are NOT interconvertible by rotation around single bonds?

Accepted Answer

Configurational stereoisomers

Answer

Configurational stereoisomers (including enantiomers and diastereomers) require bond breaking to interconvert.

Question 3

In an E2 elimination reaction, the leaving group and the beta-hydrogen must be in what relationship?

Accepted Answer

Anti-periplanar

Answer

E2 elimination requires an anti-periplanar (180°) arrangement of the leaving group and beta-hydrogen for concerted elimination.

Question 4

Which of the following correctly describes a nucleophile?

Accepted Answer

An electron-pair donor that attacks electrophiles

Answer

A nucleophile donates an electron pair to an electrophile (electron-poor site) to form a new bond.

Question 5

What product forms when an ester reacts with excess Grignard reagent followed by aqueous workup?

Accepted Answer

A tertiary alcohol

Answer

Excess Grignard adds twice to an ester (first to give a ketone intermediate, then again), yielding a tertiary alcohol.

Chemistry Practice Test

Chemistry Practice Test

Chemistry Test Organic Chemistry 2