Chapter 2: Homework Related

Question 1

How do you draw the conjugate acid of a Brønsted-Lowry base?

Answer 1

Add a proton to the base

Proton = H+

Question 2

How do you draw the conjugate base of a Brønsted-Lowry acid?

Answer 2

Remove a proton from the acid

Proton = H+

Question 3

How do you draw the products of an acid-base reaction?

Answer 3

Transfer a proton from the acid to the base

Proton = H
* remember to use arrows and adjust the charges

Question 4

Equation for pka

Answer 4

pka = -logka

Ka = 10^-pka

Question 5

How do we know if a base it strong enough to deprotonate an acid?

Answer 5

1. Draw out the conjugate acid

Eg, NH2- + H -> NH3

2. Compare the pka value of the starting acid (given) and the conjugate acid

Eh, (given acid) NH3
pka= # pka= 38

3. If the conjugate acid has a higher pka, then its base is strong enough to deprotonate the starting acid and the equilibrium favors the products because they are weaker.
   If the conjugate acid has a lower pka, then its base is not strong enough to deprotonate the starting acid and the equilibrium favors the starting materials because they are weaker than the products

Question 6

The lower the pka, the _______ the acid.

Answer 6

Stronger

Question 7

The more stable the conjugate base, the ______ acidic the acid.

Answer 7

More

Question 8

What are the 4 factors that affect acidity?

Answer 8

1. Element effects
   
   • from left to right, atoms that are more electronegative are more acidic
   • down on the ptable means more acidic
2. Inductive effects
   
   • when one molecule has more electronegative atoms, it means it withdraws (pulls) electrons, stabilizing the base and making it more acidic
3. Resonance effects
   
   • when the conjugate base of an acid has more resonance structures it means the electron pairs are delocalized, which makes the acid more stable, which makes it a stronger acid
4. Hybridization effects
   
   • the higher the % s-character, the more acidic the molecule is
   • so sp atoms are more acidic than sp3

Question 9

Lewis bases are electron pair ______.

Answer 9

Donors

• contain lone pairs or pi bonds

Question 10

Lewis acids are electron pair ______.

Answer 10

Acceptors

• contains a proton (H) or an unfilled shell of electrons

Question 11

A Brønsted-Lowry base is also a __________.

Answer 11

Lewis base

Question 12

A Brønsted-Lowry acid is a proton _______.

Answer 12

Donor

• must contain a H
• bronsted acids are ALWAYS Lewis acids
  > Lewis acids are not always bronsted acids

Question 13

A Lewis acid is a ____phile

Answer 13

Electrophile

Question 14

A Lewis base is a ____phile

Answer 14

Nucleophile