Acids and Bases EQUATIONS

Question 1

What is the equation for pH

Answer 1

pH = -log[H⁺]

Question 2

What is the equation for [H⁺]

Answer 2

[H⁺] = 10⁻ᵖᴴ

Question 3

What is the equation for K꜀ for H2O

Answer 3

K꜀ = [H⁺] [OH⁻] / [H2O]

Question 4

What is the equation for Kᵥᵥ

Answer 4

Kᵥᵥ = [H⁺]²

Question 5

What is the equation for Kₐ

Answer 5

Kₐ = [H⁺] [A⁻]/[HA]
Since [H⁺] = [A⁻] in the equation HA ⇌ H⁺ + A⁻
Kₐ = [H⁺]²/[HA]

Question 6

What is Ka

Answer 6

A weak acid approximation

Question 7

What is the equation for pKa

Answer 7

pKa = -log[ka]

Question 8

How do we get Ka from pKa

Answer 8

Ka = 10⁻ᵖᴷᵃ

Question 9

What is the equation for the dissociation of a weak acid

Answer 9

HA ⇌ H⁺ + A⁻

Question 10

If Ka is small what does this mean about the strength of an acid

Answer 10

If Ka is small - means a weaker acid (weaker, weak acid since Ka is for weak acids)

Question 11

If Ka is large what does this mean about the strength of an acid

Answer 11

If Ka is large - means a stronger acid (stronger, weak acid since Ka is for weak acids)

Question 12

If pKa is small what does this mean about the strength of an acid

Answer 12

If pKa is small - means a stronger acid (stronger, weak acid since Ka is for weak acids)

Question 13

If pKa is large what does this mean about the strength of an acid

Answer 13

If pKa is large- means a weak acid (weak, weak acid since Ka is for weak acids)

Question 14

What is the equation for the dissociation of H2O

Answer 14

H2O ⇌ H⁺ + OH⁻

Question 15

Is the dissociation of water exothermic or endothermic

Answer 15

Endothermic, +ΔH

Question 16

What is a buffer solution

Answer 16

A solution which resists changes in pH on addition of a small amount of acid, base or on dilution with water

Question 17

What the dissociation equation for making a buffer solution by adding a salt to a weak acid

Answer 17

HA ⇌ H⁺ + A⁻
(A- from salt)

Question 18

What is the equation for calculating [H+] of a buffer solution

Answer 18

[H+] = Ka x nHA/nA⁻

Question 19

What is the moles of A⁻ equal too when making a buffer by adding a base to an acid

Answer 19

nA⁻ = nOH⁻

Question 20

What is the dissociation equation when making a buffer by adding a base to an acid

Answer 20

HA + OH⁻ ⇌ A⁻ + H2O

Question 21

What is the equation to calculate the new [H+] of a buffer solution when we add an acid to it

Answer 21

nH+ = mol of H+ added

Question 22

What is the equation to calculate the new [H+] of a buffer solution when we add a base to it

Answer 22

nOH- = mol of OH- added