Organic Lab

Question 1

What is a substitution reactions?

Answer 1

A reaction in which one atom or group of atoms replaces another in an organic compound.

Question 2

What is a nucleophile?

Answer 2

A reacting group that has an unshared pair of electrons.

Question 3

The unshared electrons in the nucleophile reacts with what?

Answer 3

A site in an organic molecule that has a deficiency of electrons.

Question 4

Strong/weak bases are good nucleophiles in substitution rections.

Answer 4

Strong bases.

Question 5

Weak/strong bases are good leaving groups in nucleophilic substitution reactions.

Answer 5

Weak bases.

Question 6

In a nucleophilic substitution reaction, the weak base is the ——, the strong base is ——-, and the ——— is transferred from the weak base to the strong base.

Answer 6

Leaving group, nucleophile, carbon group.

Question 7

Name the two different mechanisms by which a nucleophilic substitution reaction may occur.

Answer 7

SN1 and SN2.

Question 8

What are the two species that react in the rate determining step of an SN2 reaction?

Answer 8

The nucleophile and the organic reactant.

Question 9

How many steps does an SN2 reaction have?

Answer 9

One.

Question 10

A back-side attack of a nucleophile to the carbon attached to the leaving group in an organic reacting causes what?

Answer 10

The configuration of the carbon atom to become inverted.

Question 11

What four factors affect the rate of an SN2 reaction?

Answer 11

1. The leaving group has to be a weak base.
2. The carbon group has to be unhindered by bulky groups. Primary carbon atoms make reaction occur faster.
3. The nucleophile has to be a strong base. But also larger nucleophile atoms are more nucleophilic.
4. The solvent has to be polar-protic in order for the reaction to occur faster.

Question 12

In SN1 reactions, only the nucleophile/organic reactant is involved in the rate determining step.

Answer 12

Organic reactant.

Question 13

In SN1 Reactions, the nucleophile reacts in a fast/slow step.

Answer 13

Fast.

Question 14

What factors affect SN1 reactions?

Answer 14

1. Leaving group must be a weak acid.
2. The carbon group forms a carbocation in the slow step. Tertiary compounds occur faster than primary compounds.
3. The solvent must be polar in order for the reaction to occur faster.

Question 15

What are solvolysis reactions?

Answer 15

Reactions that use substances in which the solvent molecules serve as the nucleophile.