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CHEMISTRY CP FINAL EXAM REVIEW
Name:
1. For each reaction below: identify the reaction type, predict the products and write the complete
balanced reaction:
Synthesis
Decomposition
Double Replacement
Single Replacement
Combustion
a. iron (III) hydroxide → iron (III) oxide and water
_ Decomposition __
________2Fe(OH)3 → Fe2O3 + 3 H2O ___________________________
b. ethylene (C2H4) burns in pure oxygen →
_ Combustion______
________ C2H4 + 3O2  2CO2 + 2H20___________________________
__ Synthesis ________
c.
magnesium + nitrogen →
_________3Mg + N2  Mg3N2_________________________________
2.
Complete and balance the reactions below in the space provided.
__2___KOH
_____ Cl2
+ _____ Pb(NO3)2
+
__2___NaBr
 _____ Pb(OH)2
+ __2___ KNO3
 _2_NaCl + Br2
3. Sodium reacts with calcium chloride to produce sodium chloride and calcium metal.
a. Balance
__2__Na + ____CaCl2 
____Ca + __2__NaCl
b. If 43.0g of calcium chloride reacts, how many grams of sodium chloride will be produced?
(ans: 45.3g NaCl)
43 g CaCl2 x 1 mol CaCl2
x 2 mol NaCl x 58.5 g NaCl = 45.3 g NaCl
111.1 g CaCl2
1 mol CaCl2
1 mol NaCl
c. The reaction above is performed in lab, and 40.0g of sodium chloride are collected. Determine the
percent error and the percent yield. (ans: 88.3% yield, 11.7% error)
% yield = 40g x 100 = 88.3% yield
45.3g
% error = 100- 88.3 = 11.7 %
4. Sodium sulfate reacts with aluminum bromide.
a. Balance:
___3__ Na2SO4 + ___2_ AlBr3  ___6__NaBr + _____Al2(SO4)3
b. Predict the mass of aluminum sulfate that will form if 25.0g of sodium sulfate react with 60.0g of
aluminum bromide. (ans: 20.1g Al2(SO4)3)
25g Na2SO4
60g AlBr3
1mol Na2SO4
142 g
1mol AlBr3
266.7 g
1mol Al2(SO4)3
3mol Na2SO4
1mol Al2(SO4)3
2mol AlBr3
342g
1mol Al2(SO4)3
342g
=
1mol Al2(SO4)3
= 20.1 g Al2(SO4)3
38.5 g Al2(SO4)3
c. The limiting reactant is: _________ Na2SO4_________________________.
5. Hydrogen reacts with nitrogen to produce ammonia (NH3). If 4.4 liters of ammonia are produced at STP,
how many grams of hydrogen reacted? (ans: 0.59g H2)
N2(g)
4.4 L NH3
1 mol NH3
22.4 L NH3
+ 3H2 → 2 NH3(g)
3 mol H2
2 mol NH3
2g H2
1 mol H2
=
0.59g H2
6. Use collision theory to explain the effect of each factor below on the rate of a chemical reaction:
a. temperature: An increase in temperature results in an increase in average kinetic energy of reactants.
This means there will be an increase in the number of successful collisions between reactants and an
increase in the rate of reaction.
b. surface area: an increase in surface area means more reactant molecules are exposed to collisions
which increases the number of successful collisions, increasing the rate of reaction.
c. stirring: means there is an increase in the probability that reactants will collide successfully more
frequently, increasing the rate of reaction.
d. adding a catalyst: Activation energy, which is the minimum amount of energy reactant particles
require for successful collisions, is decreased by the addition of a catalyst. Catalysts decrease the
activation energy by orienting reactant molecules for successful reactions. This leads to an increase in
the rate of reaction.
7. What are the three components to the kinetic theory (for gases)?
1. The particles in a gas are assumed to be small, hard spheres with an insignificant volume.
2. The motion of particles in a gas is rapid and random.
3. All collisions between gas particles and the walls of the container they are in are perfectly
elastic.
8. Use the phase diagram below to identify: a) the triple point b) the normal boiling point c) the state of the
substance at 0.5atm and 25°C and d) the change that occurs as the substance is heated from 25°C to 100ºC at
0.5atm.
a)
b)
c)
d)
1 atm
At point A
~100°C
Solid
sublimation
A
0.5atm
25
50
75
ºCelsius
100
9. List 2 ways water could be made to boil at 105°C:
a. ____add solute particles to the water (colligavtive properties)____________________
b. ___increase atmospheric pressure____________________________________________
10. Pressure and volume of a gas at constant temperature are inversely proportional. If the volume of a gas
triples, its pressure will decrease by one third
11. Volume and temperature of a gas at constant pressure are directly proportional. If the volume of a gas
triples, its temperature will triple
12. Pressure and temperature of a gas at constant volume are directly proportional. If the temperature of a gas
triples, the pressure will triple
13. If two containers are at the same temperature and pressure and their volumes are equal, they must contain
the same number of particles
14. Molecules of oxygen gas and nitrogen gas are at the same temperature in equal sized flasks. Which
molecules are moving faster? Nitrogen since one N2 molecule is lighter than one O2 molecule (N2 has a
molar mass of 28g/mol and O2 has a molar mass of 32 g/mol)
15. If the oxygen gas molecules and nitrogen gas molecules in the scenario above are all at the same
temperature, which gas has the greatest average kinetic energy? Neither - temperature is a measure of
average kinetic energy, and the temperature for both substances is the same
16. A balloon is filled with 3.0 L of helium at 1 atm. What is the volume of the balloon when the pressure is
only 0.25 atm? (ans: 12L)
Hint: Formula: P1 V1= P2V2
(1 atm)(3.0L)= (0.25atm)(x)
x= 12L
17. The gas left in a used aerosol can is at a pressure of 3.4 atm at 27.0C. If this can is thrown into a fire,
what is the pressure of the gas when its temperature reaches 500.0C? (ans: 8.8 atm)
Hint: Formula: P1 = P2
T1
T2
3.4 atm = P2
300 K
773 K
= 8.8ATM
18. 5.2 L of a gas is at STP. Find the new volume when the temperature rises to 38C and the pressure drops to
600.0 mmHg. (ans: 7.5L)
Hint: Formula: P1V1 = P2V2
T1
T2
(760mmHg)(5.2L) = (600mmHg)(V2)
273K
311K
19. Find the volume occupied by 14.0g of carbon dioxide at 25ºC and 0.880atm.
Hint: Formula: PV = nRT
14.0g CO2
1 mol CO2 = 0.32 mol CO2
44g CO2
0.88atm (V) = 0.32mol(0.0821)(298K)
V = 8.84 L
= 7.5L
(ans: 8.84L)
20. Find the molar mass of a gas if 3.0g of the gas occupy 1.7L at 25°C and 780mmHg.
Hint: Formula: PV = nRT
(ans: 42g/mol)
(780mmHg) (1.7L)= n ( 62.4 ) (298K)
n= .07mol
Molar Mass=
3.0g = 42 g/mol
.07mol
21. Find the density of Xenon gas at STP. (ans: 5.9g/L)
Hint: Formula: PV=nRT
(1atm) (1L) = n (0.0821)(273)
n=0.0446
0.0446 moles
131.3g
1 mole
=
5.9 g/1L
22. Determine the volume of oxygen gas that required for the complete combustion of 25.0g of methane gas
(CH4) at 23°C and 99kPa. (ans: 78L)
RXN: ___CH4 + 2 O2  CO2 + 2 H2O _________________________________________________
25g CH4
1 mol CH4
16g CH4
2 mol O2
1 mol CH4
=
3.125 mol
PV = nRT
99 kPa (V) = 3.125mol (8.31) (298 K)
V = 78L
23. Complete the table below describing the solubility of each solute.
SOLUTE
CBr4
KBr
CH2O
SiO2
Soluble in gasoline?
Y
N
N
N
Soluble in alcohol?
N
N
Y
N
Soluble in water?
N
Y
Y
N
24. Define hydrogen bonding:
A hydrogen bond is the electromagnetic attractive interaction between polar molecules in which hydrogen is bound to a
highly electronegative atom, such as nitrogen, oxygen or fluorine
26. Circle each of the molecules below that would exhibit hydrogen bonding: (Hint: you will need to draw
structure)
a.
HF
b. CH2O
c. NH3
d. CH4
e. H2
26. List four properties of water that are influenced by its strong hydrogen bonds.
a. high surface tension: Surface tension is a contractive tendency of the surface of a liquid that allows
it to resist an external force caused by cohesion
b. high specific heat capacity (absorbs a lot of heat as it warms up): amount of heat required to change
the temperature of an object or body by a given amount
c. cohesive forces: tendency of similar or identical particles/surfaces to cling to one another; hydrogen
bonds increase cohesiveness of water
d. density: solid water (ice) floats on liquid water; as water freezes, it becomes less dense
e. strong adhesive forces: water molecules have a strong attraction to other water molecules
27. Use the graph to answer the questions below:
a. How many grams of KClO3 need to dissolve in 50 g of water in order to have a saturated solution at
70C? ___15g _________
b. Which substance is the most soluble in water at 0C? ___ NH3__________
c. Which substance is least affected by temperature change? ____ NaCl _________
d. Which substance is the least soluble in water at 0C? ___ KClO3___________
e. Which substance becomes less soluble as the temperature increases? __ HCl, NH3__________
f. How would you describe the level of saturation of a solution of KNO3 at 40C if there are about 60g of
KNO3 in 100g of water? ___ unsaturated _________
28. Define “colligative property”: Colligative properties are properties that depend only on the # of solute
particles (concentration of the solute), and not the nature of the solute or solvent.
29. Describe the effect that a solute has on the boiling point, freezing point and vapor pressure of the solvent:
boiling point – is elevated, compared to pure solvent
freezing point – is lowered, compared to pure solvent
vapor pressure – lowers, compared to pure solvent
30. Fill in the blanks of the following paragraph:
Word bank: pressure, temperature, concentration, high, low, solvent, solute
Molarity, molality, percent by mass and volume express concentration of a solution. In order to dilute a
solution more of a solvent can be added. In order to make more concentrated solution more of a solute can be
added.
Gases are most soluble in liquids under conditions of high pressure and low temperature.
31. Determine the molarity of a solution prepared by dissolving 15.0g of KCl in 525ml of water.
Hint:
Formula: : M = mol solute
L solution
M= . 201mol = 0.383M
.525 L
15 g KCl
1mol KCl = .201 mol
74.5g
(ans: 0.383M)
32. How many grams of KCl are needed to prepare a 0.25 liters of a 3.0 M solution? (ans: 56g KCl)
Hint: Rewrite the molarity as: M = mol solute
L solution
.25L
3 mol
1L
74.6g
1mol
= 56g
33. What volume of 4.0M KCl solution is needed to prepare 750.0mL of a 0.33M solution? What volume of
water would also be needed? (ans: 62mL KCl solution, 688mL H2O)
Hint:
Formula: M1V1 = M2V2
4.0M (V) = 0.33M (750.0mL)
V = 62mL
750mL-61.9mL = 688 mL H2O
34. What volume of 2.5M hydrochloric acid is needed to react with 32.5g of aluminum?
(ans: 1.4L)
RXN: _____6 HCl + 2 Al  2 AlCl3 + 3 H2______________________________________________
32.5g Al
35.
1 mol Al
27.0g Al
6 mol HCl
2 mol Al
1L HCl
2.5 mol HCl
= 1.4L
What volume of isopropyl alcohol is in 325mL of a 75.0% isopropyl alcohol/water solution? (ans: 244mL)
75 mL iso
100 mL solution
=
x
325 mL solution
X = 244mL
36. Find the mass percent of sodium chloride in a mixture containing 45.0g of sodium chloride in 255g of
water. (ans: 15.0%)
45g solute
300g soltuion
x 100 = 15.0%
37. Write dissociation equations and determine value of “i” for the following ionic compounds:
a. KCl_____ K1+ + Cl1- ___________________________________________
i = ___2___
b. Na2SO4 ____2Na1+ + SO42- _____________________________________
i = __3____
c. the value of “ i” for molecular compounds such as C6H12O6 is ____1________
38. Determine the boiling point of a solution prepared by dissolving 40.0g of potassium nitrate in 300.0g of
water. (kf for water = 1.86°C/m, kb = 0.512°C/m)
a.
Find the molality of the solution:
(ans: 1.32m)
molality = moles KNO3
kg H20
40 g KNO3 x 1 mol KNO3 = 0.4 mol KNO3
101.1 g KNO3
b.
The value for “i” is_____2______
c.
Solve for ΔTb:
molality = moles KNO3 = 0.4 mol KNO3 = 1.32m
kg H20
0.300 kg
ΔTb = kb • m • i = (0.512°C/m)(1.32m)(2) = 1.35 °C
d.
Find the boiling point: (ans: 101.36°C)
100°C + 1.35 °C = 101.35 °C
e.
How would the problem be solved if you were looking for the freezing point of the solution?
Differences are bolded:
ΔTf = kf • m • i = (1.86°C/m) (1.32m)(2) = 4.91 °C, so 0°C – 4.91 °C = -4.91 °C
39. What is the difference (in terms of energy) between water at 100C and steam at 100C?
Steam at 100°C and water at 100°C have the same average kinetic energy (they are at the same temperature),
but steam has much more potential energy than water at the same temperature.
40. Exothermic reactions release (absorb/ release) heat; endothermic reactions absorb (absorb/ release) heat.
41. A student is heating up sodium carbonate in order to decompose it according to following reaction:
Na2CO3 (s)

Na2O (s) + CO2 (g)
Predict signs of ∆ H and ∆S for this process.
∆ H = __+___
∆ S = _+____
Under what temperature conditions will this reaction be spontaneous? Only @ high temperature
42. Predict signs of ∆S for each process:
a. NaCl (s)  Na+(aq) + Cl- (aq).
∆ S = __+___
b. FeCl2(aq) + H2SO4(aq)  FeSO4(s) + HCl(aq)
∆ S = _-____
c.
∆ S = __+___
Salt dissolving in water
d. Condensation forming on the outside of a cold glass of water
∆ S = _-____
43. Predict the amount of heat liberated when 25.0g of potassium chlorate decomposes, based on the reaction
below: (ans: 9.11kJ)
2 KClO3  2 KCl
25 g KClO3
∆ H = - 89.4kJ
+ 3 O2
1mol KClO3
89.4 kJ
122.6 g
2 mol KClO3
= 9.1 kJ
44. The data below refers to substance X.
Melting Boiling
Heat of Heat of
Specific Heat
point
Point
Fusion Vaporization Capacity (solid)
Specific Heat
Capacity (liquid)
Specific Heat
Capacity (vapor)
2.0°C
1.6 J/gºC
0.55 J/gºC
52.5C
275 J/g
1240 J/g
0.90 J/gºC
a. Draw a heating curve for substance X, going from -10ºC to 70ºC on the axis below. Write in all
formulas used to calculate heat. Label the phase present at each stage of your graph. Also label changes
in potential and kinetic energy.
70°C
Δ P. E.
G
Δ K. E.
H= m Sh ▲T
H= m Hv
52.5°
C
Δ P. E.
L
H= m Hf
Δ K. E.
H= m Sh ▲T
2°C
S
Δ K. E.
H= m Sh ▲T
-10°C
a.. Calculate the amount of heat needed to raise the temperature of 15g of this substance from 54.0°C to 67.3°C.
(ans: 109.7J)
H =m(sh)(ΔT)
H= ( 15g ) (0.55 J/gºC) (13.3°C) = 109.7 J
b.
What mass of X can be heated from 20.0°C to 35.0°C using 4000J of heat.
(ans: 166.7g X)
H =m(sh)(ΔT)
4000J = m (1.6 J/gºC) (15°C)
m = 166.7 g
c. What amount of heat will be given off if 25.5g of X are cooled from 12.0°C to -5.00°C?
STEP 1: H =m(sh)(ΔT)
H= (25.5g) (1.6 J/g ºC) (2°C -12°C) = -408 J
STEP 2: H = mHf
H= (25.5g) (275 J/g) = -7010 J
STEP 3: H =m(sh)(ΔT)
H= (25.5g) (0.90 J/gºC) (-5°C - -2°C)= -161 J
TOTAL: -408 J + -7012.5 J + -160.7 J = -7580 J
(ans: -7580J)
45. The specific heat of aluminum is 0.910J/gºC. A student heats a sample of aluminum to 123°C and places it
in a calorimeter containing 150. g of water at 23.0ºC. The final temperature of the system is 43.0ºC. What was
the mass of the aluminum sample? (ans: 172g)
Mass
specific heat
Ti
Tf
∆T
METAL
X
0.91 J/g°C
123 °C
43 °C
-80 °C
WATER
150 g
4.18 J/g°C
23 °C
43 °C
20 °C
m(sh)(ΔT) = m(sh)(ΔT)
(X)(0.91 J/g°C)(80 °C) = (150g)(4.18 J/g°C)(20°C)
X = 172g
46. Equal mass of each substance below absorbs 1000J of heat, which would become the hottest? Why?
Substance
Specific Heat Capacity
aluminum
0.897 J/g°C
iron
0.454 J/g°C
lead
0.130 J/g°C
Lowest specific heat capacities heat up fastest
47. Given the diagram below, determine the:
(include units)
a. Enthalpy of the reactants_____100kJ __________
b. Enthalpy of the products_____300kJ __________
c. Heat of the reaction, ΔH. ____300-100 = +200kJ ____________
d. Activation energy of the reaction. ___400- 100= 300kJ __________
e. Exothermic or Endothermic? . ___ Endothermic (energy of product higher than energy of
reactant)________________
48. What is the pH of a solution that has a concentration of [H+] = 1.0 X 10-6M? ___6_____
Is this solution acidic, basic, or neutral? ____ acidic _______________
49. What is the pH of a solution that has a concentration of [OH-] = 1.0 X 10-13M? ___1______
Is this solution acidic, basic, or neutral? ____ acidic _______________
50. Complete the following table:
Property
Definition
Taste
Acids
Produce H+ ions in solution
with water, or donate H+
ions
Sour
Bases
Produce OH- ions in
solution with water, or
accept H+ ions
Bitter
Touch
Not slippery
slippery
Reaction with metals
Produce H2 gas
No reaction
Electrical conductivity
Yes
yes
Reaction with indicators
(Phenolphthalein & litmus)
2 examples of strong
Litmus BR
Phenolphthalein: clear
HCl, H2SO4
Litmus R B
Phenolphthalein: pink
NaOH, KOH
51. If 25 mL of 1.5 M of HCl is required to completely neutralize 35 mL of NH4OH, what is the concentration
of the ammonium hydroxide? (ans: 1.1M)
(#H+acid name)(M acid)(Volume acid) = (#OH-base name)(M base)(Volumebase)
(1)(1.5M)(25ml) = (1)(X)(35ml)
X = (1)(1.5M)(25ml) = 1.1M
(1)(35ml)
52. How many mL of 0.5 M NaOH is needed to neutralize 16 mL of a 0.35 M H2SO4?
(#H+acid name)(M acid)(Volume acid) = (#OH-base name)(M base)(Volumebase)
(2)(0.35M)(16ml) = (1)(0.5M)(X)
X = (2)(0.35M)(16ml) = 22.4 mL
(1)(0.5M)
(ans: 22.4mL)
53. Find the molar mass and percent composition (% of each element) for calcium nitrate.
1 Ca
2N
6O
= 1 (40.1)
= 2 (14.01)
= 6 (16)
= 40.1
= 28.02
= 96
164.12
40/164 *100 = 24.39 %
28.02/164 *100 = 17.07 %
96/164 *100 = 58.54 %
% Ca _24.4%_____
%N _17.1%_______
% O _58.5%_______
54. Find the mass of 1.50 moles of dicarbon tetrachloride.
249.0 g C2Cl4
1.50 moles
166 g
1 mole
55. How many molecules are in 14.0 g of dicarbon tetrachloride.
14.0 g
1 mole
166 g
6.02 x 1023 molecules
1 mole
5.08 x 1022 molecules C2Cl4
56. Write the empirical formula for dicarbon tetrachloride.______ CCl2______________
57. A student does a lab to determine the molar mass of barium chloride. In lab, he determines the mass to be
216.0 g/mol. Find his percent error.
3.70%
BaCl2 = (1 x 137.3) + (2 x 35.5) = 208.3 g/mol (actual)
Percent error =
experimental value - actual value
actual value
Percent error = 216.0 - 208.3 x 100% = 3.56%
208.3
x 100% = 3.56%
58. Identify and give the use for each piece of lab equipment below:
watch glass- to hold solids
while being weighed, or as a cover for a beaker or
evaporating dish
beaker tongs – used to
transport a hot beaker
iron ring and a ring stand- to support the
evaporating dish – used to evaporate liquids
laboratory apparatus (ex: while heating solvent)
Erlenmeyer flask- are used in chemistry
labs for titration ; they are useful in the lab setting for
stirring the contents by hand by swirling the flask, as
the tapered neck prevents spillage of the contents.
Crucible tongs -used to grasp and take a
Test tube holders – holds test tubes when
heating
Test tube clamp – used to clamp
equipment to a ring stand
hot crucible out of a fire or to move a crucible from one
location to another.
59. Read each piece of lab equipment below:
buret
____6.63________ mL
graduated cylinder
Thermometer
____21.5________ mL
______17___________ °C