Quiz - Structure and Reactivity - 2 | Structure and Reactivity

Organic Chemistry 1 - Quiz - Structure and Reactivity - 2

1

Which of the following species can act only as a Lewis base?

NH3 has a lone pair of electrons, making it capable of donating an electron pair to form a covalent bond, which is the definition of a Lewis base. BF3 is a Lewis acid, as it accepts an electron pair. H2O and HCl can act as both Lewis bases and acids.

2

A reaction where an electrophile E+ reacts with a nucleophile Nu: to form a bond involves:

Nucleophilic substitution involves a nucleophile attacking an electrophile or a positively polarized atom, leading to the substitution of a leaving group by the nucleophile.

3

Which statement is true regarding isomers in organic chemistry?

All the given statements are true: constitutional isomers have different connectivity; stereoisomers, such as enantiomers and diastereomers, have the same connectivity but differ in spatial orientation; enantiomers are indeed non-superimposable mirror images.

4

Homolytic cleavage of a chemical bond results in the formation of:

Homolytic cleavage results in the formation of two radical species, each bearing an unpaired electron. Ions are not formed, as the electrons are divided equally.

5

Which type of arrow is used to denote the movement of a pair of electrons in a reaction mechanism?

A full-headed curved arrow signifies the movement of an electron pair in reaction mechanisms. Half-headed or 'fishhook' arrows indicate the movement of a single electron.

6

In the context of acid-base chemistry, the term 'conjugate' refers to species that:

In acid-base chemistry, 'conjugate' refers to species that differ by the presence or absence of a proton (H+). A conjugate acid-base pair consists of two species that transform into each other by gaining or losing a proton.

7

A reaction that features heterolytic cleavage is likely to produce:

Heterolytic cleavage of a bond involves one atom retaining both electrons from the bond, forming ion pairs. This contrasts with homolytic cleavage, which results in free radicals.

8

The strength of a Bronsted acid is directly related to:

The strength of a Bronsted acid is directly related to all the provided factors: the pKa value, the stability of the conjugate base, and the electronegativity of the atom to which the proton is attached.

9

Which functional group is characterized by a carbonyl group (C=O) bonded to a hydrogen atom?

Aldehydes feature a carbonyl group bonded to at least one hydrogen atom. The general structure is RCHO, where R represents an organic substituent.

10

How does the acidity of carboxylic acids change with the addition of electron-withdrawing substituents?

 

Electron-withdrawing substituents increase the acidity of carboxylic acids by stabilizing the resulting conjugate base through resonance or inductive effects.