exam equations

Question 1

henderson hasselbach equation

Answer 1

pH = pKa + log([A-]/[HA])

where A- = base conc
HA = weak acid conc

Question 2

pKa equation

Answer 2

pKa = -log(ka)

Question 3

[H+] equation

Answer 3

[H+] = 10 ^-pH

Question 4

Calcite dissolution

Answer 4

CaCO3 -> Ca2+ + CO3-

Question 5

what is Ksp

Answer 5

solubility product

Question 6

what is the equivalence point

Answer 6

pH = pKa
log ([A-]/[HA]) must be equal to 0
OR
[A-] = [HA]

Question 7

what can you add to balance equations

Answer 7

[H+]
H2O

Question 8

what else needs to be balanced

Answer 8

charges
can minus e-

Question 9

gypsum dissolution

Answer 9

Ca(SO4).2H2O -> Ca2+ + SO42- +2H2O

Question 10

IAP equation

Answer 10

same as Ksp but only times together

Question 11

is IAP &laquo_space;Ksp ?

Answer 11

undersaturated wrt the mineral

Question 12

how to do pH = pKa - pOH

Answer 12

pKa = -log(ka)

pOH = log(OH)

Question 13

what is buffering

Answer 13

slightly acidic to basic

Question 14

what is acidification

Answer 14

slightly basic to acidic

Question 15

what is a basic rule for iron in reactions

Answer 15

Fe2+ -> Fe3+ + e-

oxidation

Question 16

nerst equation

Answer 16

E = EO - [(RT/nF) In (Mn2+)]/[Mn]

Question 17

what values are needed in the nerst equation

Answer 17

gas constant = 8.314
temp = 298 K
faradgy constant = 96485
multiply by 2.303 to convert log to log10

Question 18

how to work out lifetimes

Answer 18

what you want to find on top
K then the rate constants on the bottom

cancel out to give 1/ rate constants