pH, conjugates♥
Conjugate base of H2X
HX
Does a buffer increase pH, decrease pH, or can do either?
Can do either depending on whether you put an acid or base in
Conjugate base of H3O+
Water (H2O)
Binary acids strengths increase in which direction?
Up and to the right
/ |
/
/
What are the three acid types?
Oxyacids, organic acids, binary acids
pH of a .20M solution of KCN (Ka = 6.2 x 10-10)
11.25
Which of the following will make a buffer? (Can choose multiple)
HI and NaI
HClO4 and NaClO4
HNO2 and NaNO2
HNO2 and NaNO2
Depends
Say I have a base H3X and you get H2X. It is still possible for the Ka < Kb even though it is unlikely.
Does going down the column for central atom for oxyacids increase or decrease strength?
Decrease because electronegativity goes down.
There is a column of elements,
| A |
| B |
| C |
Which kind of acid will have C as part of the strongest acid?
Binary acids due to atomic radius
If I put equal amounts (in mols, not molarities) of a strong monoprotic acid and a strong monoprotic base in water, does the pH have to be 7?
Yes, each mol makes 1 H and 1 OH which neutralize.
Which would neutralize 50 mL of .15M NaOH without undergoing a large pH change? (Can choose multiple)
40 mL .10M HF & .30M NaF
25 mL of .20M HC3H2N3O3 and .10M NaC3H2N3O3
30 mL of .25M HIO and .20M NaIO
30 mL of .25M HIO and .20M NaIO
Others o not have enough mmols to neutralize without being neutralized
Can I use the 5% rule? Ka = 3.1 x 10-8
[x]5
-----------
[20x] [5-x]
Yes, on the [5-x]
Which way does the strength of oxyacid central atoms increase strength?
Up-right
/\
/
/
What are the products of the hydrolysis of Sn(H2O)62+?
Sn(H2O)5OH- + H3O+
J, L and M are in the same column, rank the following strengths
H2JO2, H2JO4, H2JO3
H2JO4 > H2JO3 > H2JO2
pH of the buffer of
100mL of .25M KNO2 and
80mL of .40M HNO2
Ka HNO2 = 7.1 x 10-4
Using Henderson Hasselbach
pH = 3.04
Soda acid or base?
Acid (just common knowledge)
J, L, and M are in the same column
arrange the following by strength
H2LO3, H2MO3, H2JO3
H2JO3 > H2LO3 > H2MO3
If I put Iron in water, does it increase or decrease pH?
Decrease (complex ions)
for H2SeO4
Ka1 = Very Large
Ka2 = 2.2 x 10-2SeO42- < HSeO4 < H3O+
Can a H2SO4 form a buffer?
Yes, HSO4- can reach equilibrium with HSO42-
If you put the buffer H2F with a pH range of 6.1-8.1 in a HCl solution pH 10, will it make it more acidic, basic, it depends, or neither. H2F has a ka = π (<-pi)
(Don't guess, you've only got a 25% chance)
Draw out the ICE table
H2F <> HF- + H+
I ... 0 ...
C -x +x +x
E ...-x x ...+x
So, regardless of pH, or range, or Ka, your pH will have to increase because there is no HF- in the solution.
Which way would conjugate oxyacid base strength increase?
Down left (reverse of acid strength)
/
/
|/If I put Iron in water, does it increase or decrease pH?
Decrease (complex ions)