Acids, bases and equilibria

Question 1

acid def and eq?

Answer 1

substance that donates a proton (needs to contain proton ie H+) (NO ELECTRONS TRANSFERRED THIS AINT REDOX MAN) HA + H2O A- + H3O+

Question 2

base def and eq?

Answer 2

substance that accepts a proton (needs to have lone pair) B- + H2O BH + OH-

Question 3

what does strength of acid/base indicate?

Answer 3

the extent to which the substance ionises (fully, partially)

Question 4

describe the relationship between acid strength, Ka and pKa

Answer 4

strong acid -> ionises fully; Ka will be large, pK will be small.

Question 5

pH eq?

Answer 5

-log10[H3O+]

Question 6

pOH eq?

Answer 6

-log10[OH-]

Question 7

KW eq?

Answer 7

=[OH-][H3O+]=10^-14 at 25*C

Question 8

Ka?

Answer 8

[a-][H3O+]/[HA] INCLUDE UNITS - M

Question 9

Kb?

Answer 9

[BH][OH-]/[B-] INCLUDE UNITS - M

Question 10

pKa?

Answer 10

-log10[Ka]

Question 11

describe how a buffer soltion works

Answer 11

• made of weak acid and conj base. (HA, A-)
• if you add an acid it ionises forming H3O+. reacts with A- to form HA and H2O so the pH doesnt change
• add base: ionises to form OH-. reacts with HA to form H2O and A-

Question 12

henderson hasselbach equation?

Answer 12

pH = pKa + log10 [A-]/[HA] (or nA-/nHA)