page 17

Question 1

Nucleophiles as Lewis Bases:

Answer 1

Nucleophiles are Lewis bases, meaning they donate an electron pair.
They can be:
Negatively charged:
HO−, HS−, OCH3−.
Neutral molecules:
H2O, NH3 , CH3OH.

Question 2

Negatively Charged Nucleophiles:

Answer 2

Often exist as salts with counterions like
Na+,
K+ , or Li+ to balance the charge.
Example: Sodium hydroxide (
Na+OH−).

Question 3

Counterions in Reactions:
Counterions (

Answer 3

Na+,K+,Li+) are typically omitted from chemical equations because they do not affect the reaction mechanism.

Question 4

What type of species is a nucleophile in terms of Lewis theory?

Answer 4

Answer: A Lewis base (electron pair donor).

Question 5

Name two negatively charged nucleophiles.

Answer 5

Answer:
HO−, HS−.

Question 6

Name two neutral nucleophiles.

Answer 6

Answer:
H2O, NH3.

Question 7

Why are counterions like
Na+
often omitted from substitution reaction equations?

Answer 7

Answer: Their presence does not affect the reaction mechanism.

Question 8

In the reaction
CH3CH2CH2Br+Na+OH−
, what is the nucleophile?

Answer 8

Answer:
OH−

Question 9

What is the product when
CH3CH2CH2Br reacts with
OH−?

Answer 9

Answer:
CH3CH2CH2OH(1-propanol)