Acid-Base Chemistry

Question 1

List the Seven Different Strong Acids

Answer 1

1. Hydrochloric acid (HCl)
2. Nitric Acid (HNO₃)
3. Hydrobromic Acid (HBr)
4. Perchloric Acid (HClO₄)
5. Chloric Acid (HClO₃)
6. Hydroiodic Acid (HI)
7. Sulfuric Acid (H₂SO₄)

Question 2

List the Eight Different Strong Bases

Answer 2

1. Sodium Hydroxide (NaOH)
2. Potassium Hydroxide (KOH)
3. Lithium Hydroxide (LiOH)
4. Barium Hydroxide(Ba(OH)₂)
5. Calcium Hydroxide (Ca(OH)₂)
6. Rubidium Hydroxide (RbOH)
7. Strontium Hydroxide (Sr(OH)₂)
8. Cesium Hydroxide (CsOH)

Question 3

What is the definition of a strong acid?

Answer 3

An acid (HA) that completely dissociates into separate ions H⁺ and its conjugate base A^-

Similar the definition of a strong base

Question 4

How do you determine the pH of a solution given the concentration of a strong acid in aqueous solution?

Answer 4

pH=-log[H⁺]

K_a for strong acids is negligibly small

Question 5

What is the definition of a strong base?

Answer 5

A base (BOH) that completely dissociates into separate ions. Its conjugate acid, B⁺ and OH^-

Question 6

For a weak acid, what is K_a?

Remember that K is typically the symbol used for equilibrium constants

Answer 6

K_a is the equilibrium constant. Becuase strong acids readily dissociate, this value is typically too small to account for and is why we can calculate the pH of strong acids directly.

For a weak acid:

K_a = [H⁺][A^-]/[HA]

Henderson Hasselbalch = HH

pH for a weak acid can be solved using the pK_a of the weak acid along with the HH formula:

pH=pK_a+log(A^-/HA)

Question 7

What is the relationship between pK_a and K_a?

The mathematical relationship

Answer 7

pK_a=-log(K_a)

How would we consider this in terms of dissociation products?

pk_a=-log([H⁺][A^-]/[HA]) becuase K_a = [H⁺][A^-]/[HA]

So we are just substituting the equation for K_a in place of K_a in the equation for pK_a

Question 8

What is an Arrhenius Acid/Base?

Definition Card

Answer 8

An Arrhenius Acid/Base is a compound that forms either hydronium ions (acid) or hydroxide ions in solution. This is an older description of acids/bases that the Bronsted-Lowry theory, however, these theories are essentially equivalent.

Hydronium ion - H₃O⁺
Hydroxide ion - OH^-

Question 9

What is a Bronsted-Lowry Acid/Base?

Definition Card

Answer 9

A Bronsted-Lowry acid (sometimes referred to as just a Bronsted acid) is a substance that donates a proton. While a Bronsted base will acts as a proton acceptor. The only difference is that the Arrhenius definition is considering the autoionization of water, limiting its definition to aqueous systems.

Question 10

What is a Lewis Acid/Base?

Definition Card

Answer 10

A Lewis acid is compound that will act as an electron pair acceptor, while a Lewis base is a compound that will act as an electron pair donator. Many nucleophiles covered in organic chemistry are Lewis bases. In fact Lewis bascicity and nucleophilicity are very similar concepts and can sometimes be used interchangeably.

Question 11

What is the equation for the autoionization of water?

Answer 11

H₂O_(l) + H₂O_(l) ↔ H₃O⁺_(aq) + OH^-_(aq)

Question 12

What does amphiprotic mean? What is an example of an amphiprotic substance?

Answer 12

Amphiprotic describes compounds that can either donate or accept a proton (act as both a Bronsted acid and base). Water is perhaps the most abundant amphiprotic compound. Many amino acids are also amphiprotic (perhaps all).

Question 13

What is the Henderson-Hasselbach equation?

Answer 13

pH = pK_a + log([A^-]/[HA]

Used with weak acids/bases