Proton transfer, acid-base chemistry, redox equilibria

Question 1

How do you work out the ionic product of water?

Answer 1

Kw = [H3O+][OH-] = 1×10^-14

Question 2

What ions do acids produce in aqueous solutions?

Answer 2

H+ / hydronium ions H3O+

Question 3

What ions do bases produce in aqueous solutions?

Answer 3

OH-

Question 4

How are protons transferred in an acid-base reaction?

Answer 4

Proton is transferred from one acid to a base, with formation of another weaker acid + base.

Question 5

What are conjugate acid/base pairs?

Answer 5

Pairs of substances which differ by a single proton.

Question 6

What are amphoteric substances?

Answer 6

Substances that can accept or donate protons - acts as either an acid or base.

Question 7

Does ‘strength’ of an acid equal concentration?

Answer 7

Strength does NOT equal concentration!

Question 8

What does the acid ‘strength’ of an aqueous solution depend on?

Answer 8

Concentration of hydronium ions (H3O+)
- conc of H3O+ α acidity

Question 9

How do you find the pH with H3O+?

Answer 9

-log10[H3O+]

Question 10

How do you find [H3O+]?

Answer 10

10^-pH

Question 11

What does Kw control the balance of?

Answer 11

H3O+ and OH-

Question 12

What is [H3O+] compared to [OH-] when the pH is 7?

Answer 12

neutral so [H3O+] = [OH-]

Question 13

What is [H3O+] compared to [OH-] in acidic solutions?

Answer 13

[H3O+] > [OH-]

Question 14

What is [H3O+] compared to [OH-] in alkaline solutions?

Answer 14

[H3O+] < [OH-]

Question 15

How do strong acids diff to weak acids?

Answer 15

They completely ionizes in aqueous solutions

Question 16

How do weak acids diff to strong acids?

Answer 16

They partially dissociate in water to form a few ions in aqueous solutions

Question 17

Do strong acids have strong or weak conjugate bases?

Answer 17

Weak - effectively do not function as bases

Question 18

What conjugates do weak acids/bases have?

Answer 18

Weak conjugates

Question 19

Do strong bases have strong or weak conjugate acids?

Answer 19

Weak - effectively do not function as acids

Question 20

What is the Henderson-Hasselbalch equation for acids?

Answer 20

HA + H20 ⇌ A- + H30+

Question 21

What is Ka?

Answer 21

acid dissociation constant

Question 22

What is the Ka of acids in the Henderson-Hasselbalch equation?

Answer 22

Ka = [A-][H30+] / [HA]

Question 23

How do you find pKa from Ka?

Answer 23

pKa = -log10[Ka]

Question 24

What is the pH of acids in the Henderson-Hasselbalch equation?

Answer 24

pH = pKa + log10[A-]/[HA]

Question 25

What is the Henderson-Hasselbalch equation for bases?

Answer 25

B + H20 ⇌ BH+ + OH-

Question 26

What is the Kb of bases in the Henderson-Hasselbalch equation?

Answer 26

Kb = [OH-][BH+] / [B]

Question 27

What is the pOH of bases in the Henderson-Hasselbalch equation?

Answer 27

pOH = pKb + log10[BH+]/[B]

Question 28

How do you work out Kw for acid-base conjugate pairs?

Answer 28

Ka x Kb = Kw pKa x pKb = pKw

Question 29

What pH is pKw at RT?

Answer 29

pH 14

Question 30

How do you find pKw from Kw?

Answer 30

pKw = -log(Kw)