3H2 + N2  2NH3 ΔH=-92.0kJ/mol
Shift? Effect on K?
Increase Volume?
 No effect
Add Helium Gas?
No effect No effect
Decrease temperature?
 increase K
pH of 0.00350M HNO3?
pH=2.46
pH of 0.00350M HOCl?
pH=4.96
pH of 0.00350M NaC2H3O2
pH=8.14
pH of 0.00350M C5H5NHBr
pH=3.84
pH of 0.00350M Sr(OH)2?
pH=11.85
A 2.0M weak acid is 15.0% dissociated. Ka?
pH=.0529
A buffer is 0.50M propanoic acid (Ka=1.3x10-5) and 0.40M sodium propanoate in a
1.0L volume. Calculate pH?
pH=4.79
A buffer is 0.50M propanoic acid (Ka=1.3x10-5) and 0.40M sodium propanoate in a
1.0L volume. Calculate pH after 0.060moles of NaOH is added?
pH=4.91
A buffer is 0.225M acetic acid(Ka=1.8x10-5) and 0.225M sodium acetate in a
250mL volume. Calculate pH of buffer.
pH=4.74
A buffer is 0.225M acetic acid(Ka=1.8x10-5) and 0.225M sodium acetate in a
250mL volume. Calculate pH of buffer after 30.0 mL of 0.100M HCl is added.
pH=4.70
Which of the following combinations cannot produce a buffer solution?
(a) HNO2 and NaNO2
(b) HCN and NaCN
(c) HClO4 and NaClO4
(d) NH3 and (NH4)2SO4
(e) NH3 and NH4Br
Calculate the ratio [CH3COOH]/[NaCH3COO] that gives a solution with pH =
5.00?
(a) 0.28
(b) 0.36
(c) 0.44
(d) 0.56
(e) 1.82
How many grams of NaF would have to be added to 2.00 L of 0.100 M HF
(Ka=7.2x10-4) to yield a solution with a pH = 4.00?
(a) 300 g
(b) 36 g
(c) 0.84 g
(d) 6.9 g
(e) 60. g
Consider the titrations of the pairs of aqueous acids and bases listed on the left.
For which pair is the pH at the equivalence point stated incorrectly?
Acid-Base Pair
pH at Equivalence Point
(a) HCl + NH3
less than 7
(b) HNO3 + Ca(OH)2
equal to 7
(c) HClO4 + NaOH
equal to 7
(d) HClO + NaOH
less than 7
(e) CH3COOH + KOH
greater than 7
Which of the following salts give acidic aqueous solutions? Basic?
KNO3
KCH3COO
NH4NO3
RbI
(NH4)ClO4
BaCl2
NaCN
KNO2
Acids-NH4NO3 and NH4ClO4
Bases-KCH3COO and NaCN and KNO2
Consider an indicator that ionized as shown below for which its Ka = 1.0 x 10-4
HIn
yellow
+ H2 O
H3O+ + Inred
Which of the responses are true?
(1) The predominant color in its acid range is yellow.
(2) In the middle of the pH range of its color change a solution containing the
indicator will probably be orange.
(3) At pH = 7.00, a solution containing this indicator will be red.
(4) At pH = 7.00, most of the indicator is in the un-ionized form.
(5) The pH at which the indicator changes color is pH = 4.
Ksp
Ag2CrO4
9.0 x 10-12
BaCrO4
2.0 x 10-10
PbCrO4
1.8 x 10-14
The chromate that is the most soluble in water at 25oC on a molar basis is:
(a) Ag2CrO4
(b) BaCrO4
(c) PbCrO4
The molar solubility of PbBr2 is 2.17 x 10-3 M at a certain temperature. Calculate
Ksp for PbBr2.
(a) 6.2 x 10-6
(b) 6.4 x 10-7
(c) 4.1 x 10-8
(d) 3.4 x 10-6
(e) 1.4 x 10-5
For Cu(OH)2, Ksp = 1.6 x 10-19. What is the molar solubility of Cu(OH)2?
(a) 3.4 x 10-7 M
(b) 6.4 x 10-7 M
(c) 2.7 x 10-11 M
(d) 5.1 x 10-10 M
(e) 1.7 x 10-10 M
Ag3PO4 (Ksp=1.8x10-18) would be least soluble at 25oC in
(a) 0.1 M AgNO3
(b) 0.1 M HNO3
(c) pure water
(d) 0.1 M Na3PO4
At 200˚C, the Keq is 550. At 300˚C, the Keq is 0.211. Is the reaction exothermic
or endothermic?
Exothermic
What is the net ionic equation for the aqueous reaction of nitric acid and lithium
hydroxide?
H+ + OH-  H2O
Write the reaction when a concentrated solution of ammonia is added to a
suspension of zinc hydroxide.
Zn(OH)2 + 4NH3  [Zn(NH3)4]2+ + 2OH-
Write the reaction when excess concentrated sodium hydroxide solution is added
to solid aluminum hydroxide.
Al(OH)3 + 3OH-  Al(OH)63-