Semester 2 Final Review Packet 2010
Solutions:
1. What is the difference between a suspension, colloid, and solution?
See pg476
2. Calculate the boiling point of a solution containing 7.58g of C 10H8 in 120.0g of benzene. The boiling point of
benzene is 80.1oC and the Kb = 2.53 oC/m.
81.30C
3. What is the molality of an aqueous solution, when a molecular compound is the solute that boils at 101.02oC?
(when the Kb of water is 0.512 oC/m)
2.0m
4. What mass of KCl (34.0 g/100.0 g water) will produce a saturated solution in 500.0g of water at 20.0oC?
170.g
5. Draw a general solubility curve for a gas and a soluble solid.
See figure 14.15 and assume cerium sulfate is a gas
a. How are these curves different?
b. How can you use this chart to determine if something is saturated, unsaturated, or supersaturated?
6. Calculate the molarity of the following solutions:
a. 0.40 mol of NaCl dissolved in 1.6 L of solution 0.25M
b. 20.2 g of potassium nitrate, KNO3, in enough water to make 250.0 mL of solution. 0.799M
7. You must prepare 300.0 mL of 0.750 M NaBr using a 2.00 M stock solution. How many milliliters should you
use?
113mL
8. In order to dilute 1.0 L of a 6.00 M solution of NaOH to a 0.500 M solution, how much water should you
add?
You must add 11L of water to the 1L of NaOH stock solution
Rates of Reactions:
1. List 3 ways reaction rate can be increased. Why?
Pg. 563
2. How would the equilibrium position of the following reaction be affected if:
2N 2 O 5 (g)  4NO2 (g)  O 2 (g)
a. An addition of O2 to the reaction vessel
left
b. A decrease in pressure
right
c. Write the Keq for this equilibrium
Keq = ( [ O2] [NO2]4 ) / [N2O5]2
3. When gently warmed, the element iodine will sublime (I2 (s)  I2 (g)). Is this process accompanied by an
increase or decrease in entropy?
Increase = more disorder
4. Is there an increase or decrease in entropy when air is cooled and liquefied? decrease
Energy:
1. The enthalpy of a system is the same as its:
A specific heat
B heat of reaction
C heat content
D potential energy
2. The SI unit of heat and energy is
A heat capacity
B joule
C moles
D calorie
3.
The amount of heat needed to raise the
temperature of 1 gram of a substance 1°C
A specific heat
B heat of reaction
C a mole
D kinetic energy
4.
5.
6.
Boiling water is
A exothermic and increasing in temperature
B endothermic and increasing in
temperature
C exothermic and constant temperature
D endothermic and constant temperature
The heat capacity of aluminum is 24.4
J/mol • °C. How much energy is released when
5.00g Al is cooled from 50°C to 30°C?
A 2440 J
B 90 J
C 3.7 J
D 488 J
Evaporation is a cooling process because
A The particles with the lowest amount of
energy escape first
B The container cools off the liquid inside
C The particles freeze
D The particles with the highest with the
highest amount of energy escape first
7. When NaHCO3 is put into water the solution
made is
a. basic
b. neutral
c. acidic
d. I have no idea!
8. When Mg(ClO4)2 is put in water the solution is
a. basic b. neutral
c. acidic
9. A high Ksp value suggests the salt is
a. very soluble
b. very insoluble
c. we can’t tell from the Ksp
10. Using the unbalanced equation given, calculate
the value of Keq given the concentration date
of: [NH3] = 0.933 mol/L, [N2] = 0.533 mol/L
and [H2] = 1.600 mol/L.
N2 (g) + H2 (g)  NH3 (g)
a. 0.235
b. 1.23
c. 0.399
d. 22.4
11. What is the concentration of silver ions in a
1.0L saturated solution of silver carbonate.
The Ksp of silver carbonate is 8.1x10-12.
2.5 x 10 -4
12. Calculate the ΔH of the following reaction.
Refer to the back of your text book (pg. 975)
to find the ΔH values.
4NH3 (g) + 5O2 (g)  4NO (g) + 6H2O (l)
1166kJ/mol
Acids and Bases:
1. Name the following acids and identify if they are strong acids.
a. HNO2, nitrous acid
H2SO4, sulfuric acid (strong acid)
HF,
hydroflouric acid
H2CO3 carbonic acid
2. Describe acids and bases
See chapter 18
3. A solution has a H+ concentration of 1x10-6 M. What is its pH?
6.0
4. What is the pOH of a solution if the [OH-] = 3.5x10-2 M.
1.46
5. What is the pOH is a solution has a pH of 3.4?
10.6
6. Classify each solution as acidic, basic or neutral;
a. [H+] = 2.5x10-9 M
basic
c. [OH-] = 9.8x10-11 M
acidic
-7
b. pOH = 12.0
acidic
d. [H+] = 1x10 M
neutral
7. Write the equation showing the ionization of H2SO4 in water. Label the conjugate acid-base pairs.
Acid = H2SO4 base = water CA = H3O+
CB = HSO4 18. Classify the following acids as monoprotic, diprotic or triprotic.
a. H2SO3
diprotic
b. HBr
monoprotic
c. H3ClO4 triprotic
9. Write the Ka or kB for the following weak acids:
a. H2S,
NH3,
C6H5COOH
10. What two things ALWAYS make-up a buffer solution? Pg 666
11. What is the molarity of a sodium hydroxide solution if 38 mL of the solution is titrated to the end point
which 14 mL of 0.75 M sulfuric acid? 0.55M
12. What volume of 0.12 M Ba(OH)3 is needed to neutralize 12.2 mL of 0.25 M HCl?
8.5mL
13. A buffer solution is prepared by mixing equal quantities of formic acid (HCHO 2) and sodium formate
(NaCHO2). Write equations that show what happens when first acid, then base is added to this buffer
solution. Why doesn’t the pH change when a buffer is used. See pg. 666-667
Redox:
1. Determine what is oxidized and what is reduced in each reaction. Identify
reducing agent:
a. 2Li + S  Li2S
Oxidized Reduced
A
Li
S
b. 3Mg + N2  Mg3N2
B
Mg
N
C
Br
Cl
c. Cl2 + 2NaBr  2NaCl + Br2
D
Na
H
the oxidizing agent and the
OA
S
N2
Cl2
Na
d. 2Na + 2H2O  2NaOH + H2
2. Calculate the oxidation number for chromium in each of the following formulas:
a. Cr2O3 +3
b. H2Cr2O7
+6
c. CrSO4
+2
d. CrO42-
RA
Li
Mg
NaBr
H2O
+6
3. Use half-reactions to balance the following reactions:
a. 5Fe2+ + MnO4- + 8H+  5Fe3+ + Mn2+ + 4 H2O (acidic solution)
b. 3Sn2+ + IO3- + 6H+  3Sn4+ + I- + 3H2O (acidic solution)
c. Mn2+ + H2O2  MnO2 + H2O (basic solution)
2OH- + H2O2 + Mn 2+  MnO2 + 2 H2O
4. Draw the following voltaic cell. Be sure to include e- flow, ion flow, label ions in solution, label the cathode
and anode, and write half reactions for each cell along with a balanced cell reaction:
a. Ag+ (aq) + Ni (s)  Ag (s) + Ni 2+
5. Write the following voltaic cell in shorthand notation: Mg (s) + Cl2 (aq)  2Cl- (g) + Mg2+
a. Calculate the standard cell potential for this using your textbook. -3.730 V
b. Would this reaction happen spontaneously in the reverse direction? Why?
The reverse reaction would not happen spontaneously because that would be forcing the “unlikely”
to happen. Mg is highly electronegative so it wants to lose electrons so if it was reversed then you
are forcing Mg to gain electrons and it doesn’t “like” to do that
O-Chem:
1. Name the following hydrocarbons:
CH3
CH3
CH3 – CH2 – CH2 – C – CH2 – C – CH3
CH2
CH2
CH3
CH3
5-ethyl-3,3,5-trimethylocttane
CH3
CH3
CH3 – CH – C – CH2 – C – CH2 – CH3
H 3C
CH2
3-ethyl-2,3,5,5-tetramethylheptane
CH3
CH3
2. Write the structural formulas for the following compounds:
a. 3-ethyl-2,3-dimethylpentane
b. 3,4-diethyl-1-hexene
c. 2,3,4,5-tetramethylnonane
3. Name the following alkenes
a. CH3-CH=CH-CH2-CH3
b. CH2=CH-CH3
2-pentene
1-propene
4. Name and draw all of the alkynes with the molecular formula C 5H8.
5. Draw and name three-carbon examples of the following functional groups:
a. Alcohol
c. Carboxylic acid
b. Ester
d. Ether
c. Aldehyde
e. Ketone
d. Halocarbon
Nuclear:
1. What happens to the mass number and atomic number if
a. An atom undergoes alpha decay
mass number goes down 4, atomic down 2
b. An atom undergoes beta decay
mass number same, atomic up 1
c. An atom undergoes gamma decay
mass number and atomic number don’t change
2. Complete each of the following equations:
a.
14
6
b.
241
95
c.
16
7
3. Write
a.
b.
c.
C  10 e  ? nitrogen - 14
Am 24 He  ? neptunium - 237
N 168 O  ? beta particle
a nuclear equation for the following radioactive process:
Alpha decay of francium-208
Positron emission by fluorine-17
Beta emission by argon-37
4. Polonium-214 has a relatively short half-life of 164 seconds. How many seconds would it take for 8.0 g of
this isotope to decay to 0.25 g?
820 seconds
5. What is the difference between fusion and fission
see pg878, 883
6. How can we use nuclear chemistry (aka: radioactive materials) in a good way? see chapter 24
7. A substance has a half life of 2hours, If we began an experiment with 152 g of this isotope, approximately
how much would remain after 24 hours?
0.0371g