Acids and Bases

Question 1

What is a Brønsted–Lowry acid?

Answer 1

Donates protons (H⁺)

Question 2

What is a Brønsted–Lowry base?

Answer 2

Accepts protons (H⁺)

Question 3

What is a Lewis acid? Lewis base?

Answer 3

• Lewis acid: acccepts lone pairs
• Lewis base: donates lone pairs

The Lewis-acid base interaction between a metal cation and an electron pair donor is called a coordinate covalent bond, complex ion formation or nucleophile–electrophile interactions.

Question 4

[Mnemonic]

PAD: acid donates protons

BAP: base accepts protons

(how to remember the function of a Brønsted–Lowry acid and base)

Answer 4

PAD: acid donates protons

BAP: base accepts protons

Question 5

[Mnemonic]

Lewis acid is an electron acceptor.

(how to remember the function of a Lewis acid)

Answer 5

Lewis acid is an electron acceptor (accepts a lone pair).

Question 6

What is the difference between the Brønsted–Lowry and Lewis definitions of acids and bases?

Answer 6

• Brønsted–Lowry: transfers protons
• Lewis: transfers electrons

(focuses on the attack of the Lewis acid (electrophile) by the lone pair of the Lewis base (nucleophile)

Question 7

What does the Arrhenius definition of acids and bases state?

Answer 7

Acids: produce H⁺ ions when dissolved in water (aq)

Bases: produce OH^- ions when dissolved in water (aq)

Question 8

[Mnemonic]

BrOnsted-LOwery: prOtOns
LEwis: Electrons
ArrHenius: H⁺/OH^-

(how to remember what each theory of acids and bases deal with)

Answer 8

BrOnsted-LOwery: prOtOns
LEwis: Electrons
ArrHenius: H⁺/OH^-

Question 9

What is an amphoteric species?

Answer 9

A substance that can act as an acid OR base.

Examples: Water (H₂O), Al, Zn, Pb, Cr, HCO₃^-

Question 10

What is the process of autoionization of water (self-ionization)?

Answer 10

When water reacts with itself because it is amphoteric.

Question 11

What are the strengths of acids and bases determined by?

Answer 11

Reaction arrows

• A single-headed arrow indicates a strong acid or base. (complete dissociation with NO reversibility)
• A double-headed arrow indicates a weak acid or base.

Question 12

What is the water dissociation constant (K_w)?

Answer 12

K_w = [H₃O⁺][OH⁻]

Question 13

The water dissociation constant (K_w) is an equilibrium constant. What change has an effect on K_w?

Answer 13

Temperature

Question 14

What is the equation for pH and pOH?

Answer 14

Question 15

What are strong acids and bases?

Answer 15

Acids and bases that completely dissociate (or ionizes) into their component ions in aqueous solutions.

Question 16

What are weak acids and bases?

Answer 16

Acids and bases that partially dissociate in aqueous solutions.

Question 17

What are the six strong acids?

Answer 17

1. Hl
2. HCl
3. HBr
4. HNO₃ (nitric acid)
5. H₂SO₄ (sulfuric acid)
6. HClO₄ (perchloric acid)

Question 18

What are the three strong bases?

Answer 18

1. NaOH
2. KOH
3. CaOH₂

(Group 1A Hydroxides also!)