SCH4U1 FINAL EXAM REVIEW

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1
SCH4U1 FINAL EXAM REVIEW
UNIT 2: ATOMIC THEORY AND BONDING
1. A certain type of electromagnetic radiation has a frequency of 8.0 x 1013 Hz.
a) Calculate the wavelength of this radiation.
b) Calculate the energy (in kJ/mol) of this radiation.
2. Calculate the frequency of radiation which has an energy of 1634 kJ/mol.
3. Calculate the energy that is released when an electron moves from energy level 6 to energy
level 2 in an excited hydrogen atom.
4. Write the complete electron configuration of each of the following:
a) S
b) K
c) Rh
d) Eu
5. For each of the following, write the short (abbreviated) electron configuration and draw the
energy level diagram.
a) S2b) Cu
c) Pb4+
d) Zn2+
6. State a set of quantum numbers to represent one electron in each orbital:
a) 2s electron
b) 2px electron
c) 5dxy electron
7. For the elements Na, Si, Cl and Cs, which of the elements has:
a) The highest first ionization energy
b) The highest second ionization energy
c) The smallest atomic radius
d) The most metallic character
8. For each pair, identify the substance with the smaller radius.
a) K, Br
b) S, Se
c) O2- ion, F- ion
d) Na+ ion, Al3+ ion
9. Using electronegativity values, classify the bonding in each substance as covalent, polar covalent
or ionic.
a) K2O
b) BeO
c) KH
d) SiF4
e) KCl
f) CBr4
10. Draw the orbital representation of bonding, Lewis structure and electron dot diagram for each
of the following:
a) H2O2
b) C2H4
c) C2H2
d) NH4+
e) H3O+
f) cyanide ion (CN-)
g) sulfate ion (SO42-)
1
2
11. For each of the following, draw the molecular shape and state whether it has a molecular dipole
(assume each compound is molecular):
a) AlCl3
b) PH3
c) H2S
d) SeF6
e) CF4
12. For the following substances:
Substance
1
2
3
4
5
m.p. (oC)
1535
801
-272
1713
52
b.p. (oC)
3000
1413
-265
2590
265
Electrical Conductivity
Solid State
Liquid State
Yes
Yes
No
Yes
No
No
No
No
No
No
Solubility in
Water
No
Yes
No
No
No
Which of these substances is most likely to be:
a) an ionic solid
b) a covalent network solid
c) a metallic solid
d) a molecular solid
e) an atomic solid
13. Which of the substances listed below:
a) are held together by only van der Waals (London) intermolecular forces.
b) are atomic solids
c) are non-polar molecular solids
d) are metallic solids
e) are covalent network solids
f) are ionic solids
g) conduct electricity in the solid state
h) conduct electricity when melted
i) is held together by hydrogen intermolecular bonding.
CCl4, CH2O2, C2H4, SiO2, C (s, diamond), Kr, Na, CsCl, Al, KF, Ne
14. a) Which of the atomic solids in Q. 13 would have the highest boiling point?
b) Which of the molecular solids in Q. 13 would have the highest boiling point?
c) Which of the metallic solids in Q. 13 would have the highest boiling point?
d) Which of the ionic solids in Q. 13 would have the highest boiling point?
Answers:
1. a) 3.8 x10-6 m b) 5.3 x 10-23 kJ/atom; 32 kJ/mol
Remaining answers poste don Ridge Science website.
2
2. 4.09 x 1015 Hz
3. 292 kJ/mol released
3
UNIT 3: ENERGY AND RATES OF REACTION
1. Write each equation using H notation and state if the reaction is exothermic or endothermic.
a) SO2 (g) + ½ O2 (g)

SO3 (g) + 38 kJ
b) Ca(OH)2 (s) + 64.9 kJ

H2O (l) + CaO (s)
c) 6C (s) + 3H2O (l) + 902 kJ

C6H6 (l) + 3/2 O2 (g)
d) N2 (g) + 3H2 9g)

2NH3(g) + 92 kJ
2. Heptane undergoes complete combustion with oxygen to produce carbon dioxide gas and water
vapour.
a) Write a balanced equation for the reaction and predict the sign of H.
b) Given the following information and the values on the periodic table, calculate H using Hess’
Law:
7C(s) + 8H2(g) 
C7H16 (l)
Hf = +121 kJ/mol
2
c) How much energy would be released if 5.00 x 10 g of heptane undergoes combustion?
3. Sodium hydroxide undergoes an exothermic reaction when dissolving:

NaOH (s)
Na+ (aq) + OH+ (aq)
+
energy
When 40.8 g of sodium hydroxide was dissolved in 1.30 L of water, the temperature of the
water increased by 46.0 oC. Calculate H in kJ/mol.
4.a) Write the nuclear reaction for the alpha decay of sodium-23 (2311Na).
b) Write the nuclear reaction for the beta decay of carbon-14 (14cC).
c) Write the nuclear reaction for the gamma decay of nickel-60 (6028Ni).
d) Write a nuclear reaction for the decay of 32P into 32S and predict the radioactive particle formed.
e) Write a nuclear reaction for the following neutron bombardment reaction: 7Be (n, p+)
5. How much energy (in kJ/mol) will be released by the following fusion reaction?
4 11H
+
5 10n 
9
4Be
(mH = 1.00782522 g/mol; mn = 1.00807134 g.mol; mBe = 9.01220010)
6. Using the average bond energy values from the periodic table, calculate the enthalpy change for
the following reaction:
C2H4 (g) + 3O2 (g)  2CO2 (g) + 2H2O (g)
3
4
7. In the incomplete combustion carbon, C (s), 74.0 g of oxygen gas reacts in 20.0 minutes. Calculate
the rate of the reaction in terms of moles CO(g) produced per hour:
C (s) + O2 (g)  2CO(g)
8. a) Sketch a potential energy diagram for this reaction and label it completely. Assume an initial
P.E. value of 10 kJ/mol: A + B  C
H = -25 kJ/mol; Ea = 70 kJ/mol
b) Using the graph determine the enthalpy change and activation energy for the reverse reaction.
9. Explain how a catalyst works to increase the rate of a reaction by describing:
a) its effect on the kinetic energy distribution curve (Boltzmann distribution)
b) its effect on the potential energy diagram of a chemical reaction.
c) Repeat this question to explain the effect of temperature on the rate of reaction.
10. Consider the following reaction:
KMnO4 (aq) + H2O2 (aq) → MnO2 (aq) + KOH (aq) + H2O (l) + O2 (g)
r = cO2/t
The initial rate of reaction was monitored by measuring the moles of oxygen produced per
second and the following kinetic data collected.
Trial
1
2
3
4
5
6
[KMnO4] (mol/L)
0.001
0.002
0.003
0.004
0.004
0.004
[H2O2] (mol/L)
0.004
0.004
0.004
0.001
0.002
0.003
Rate (mol/s)
0.003
0.012
0.027
0.002
0.016
0.054
a) Determine the rate law equation for the reaction.
b) What is the overall order of this reaction?
c) By what factor would the reaction rate increase if both [KMnO4] and [H2O2] were tripled at
the same time?
Answers:
1. a) ΔH = -88 kJ/mol; exo b) ΔH = +64.9 kJ/mol; endo c) ΔH = +902 kJ/mol; endo d) ΔH = -92 kJ/mol; exo
2. b) -4815 kJ/mol c) 2.40 x 104 kJ
3.-245 kJ/mol KOH
23
19
4
14
14
4. a) 11Na  9F + 2He b) 6C  7N + 0-1e c) 608Ni  6028Ni + 00 d) 3215P  3216S + 0-1e
e) 74 Be + n  73 Li + 11p
5. 5.35 x 109 kJ 6. -1059 kJ
7. 13.9 mol CO/h
2
3
10. a) r = k[A] [B] b) 243x
4
5
UNITS 4 AND 5: EQUILIBRIUM THEORY & APPLICATIONS
1. Consider the equilibrium:
H2 (g) + O2 (g) ⇌ H2O (g) H = -242 kJ
What would happen to the equilibrium concentrations of each of the substances when the
following changes are made?
a) increasing [H2O]
b) increasing the temperature
c) increasing the volume of the container
d) increasing the pressure
2. Consider the equilibrium:
N2 (g) + 3H2 (g) ⇌ 2 NH3 (g)
H = -92 kJ
What conditions will increase the equilibrium concentration of ammonia?
3. Describe the 5 characteristics of a reaction system that is at equilibrium.
4. Consider the equilibrium:
A (g) + 2B (g) ⇌ C (g) + D (g) + energy
What affect (if any) do the following changes have on the concentrations of A, B, C and D?
a) increase [D]
b) decrease temperature
c) decrease volume (increase pressure)
5. Consider the equilibrium:
PCl5 (g) ⇌ PCl3 (g) + Cl2 (g) K = 0.129
At equilibrium, [PCl5] = 0.235 mol/L and [PCl3] = 0.174 mol/L. Calculate the concentration of chlorine
at equilibrium.
6. Consider the equilibrium:
2 NH3 (g) ⇌ N2 (g) + 3H2 (g)
When 15 g of ammonia is placed in a 5.0 L container and equilibrium is established, the concentration
of nitrogen is determined to be 0.070 mol/L.
a) Calculate the initial concentration of ammonia.
b) Calculate the equilibrium constant (K) value.
7. What anion can be used to separate Li+ (aq) from Pb2+ (aq)?
8. The solubility of Mg(OH)2 is 9.12 x 10-3 g/L. Calculate the solubility product (Ksp) value.
9. If 19.6 g of BaI2 (s) is dissolved in 2.5 L of a 3.0 x 10-11 CuNO3 (aq) solution, will a precipitate form?
(Ksp(CuI) = 1.1 x 10-12)
10. The Ksp value for barium sulfate is 1.5 x 10-9. Calculate the maximum mass of BaSO4 (s) that will fully
dissolve in 3.0 L of water.
5
6
11. a) Calculate the hydronium and hydroxide concentrations in a solution made by dissolving 4.00 g of
NaOH in 10.0 L of water.
b) What is the pH and pOH of the solution?
12. Calculate the hydronium and hydroxide concentrations in a solution made mixing 60.0 mL of 0.400
mol/L HCl and 50.0 mL of 0.400 mol/L NaOH.
13. What is the hydronium and hydroxide concentration of pure water at 10oC
Kw = 2.95 x 10-15 at 10oC
14. If 20.0 mL of 0.050 mol/L HCl (aq) is required to neutralize 80.0 mL of NaOH (aq), determine the
concentration of the base.
15. In a titration, 1.60 g of an unknown acid “HX” is dissolved in 50.0 mL water and titrated with base.
If 70.0 mL of 0.200 mol/L NaOH is required to reach the endpoint, calculate the molar mas sof HX.
16. What is the percentage by mas s (% m/m) of acetic acid (ethanoic acid; CH3COOH) in a sample of
vinegar if 45.00 mL of 0.500 mol/L NaOH is required to titrate a 25.00 mL sample of the vinegar to
the phenolphthalein endpoint. Dvinegar = 1.06 g/mL
17. A 0.020 mol/L solution of a weak acid “HX” has a pH of 2.80. Find the Ka of the acid.
18. Given benzoic acid has a Ka = 7.0 x 10-5 , calculate the [H3O+] for a 0.0085 mol/L solution of this weak
acid.
19. A 1.0 L solution is prepared by dissolving 0.20 mol HF and 1.0 mol KF.
a) Write the Bronsted-Lowry acid-base equation of HF reacting with water and write the Ka
equation.
b) Create an ICE table. Assume that KF dissociates 100%.
c) Calculate the [H3O+] and pH of the solution. Ka = 6.67 x 10-4
20. Methylamine (aminomethane) is a weak base with Kb = 4.37 x 10-4 .
a) Write the Bronsted-Lowry acid-base equation for CH3NH2 reacting with water.
b) If 10.0 L solution of methylamine is found to have a pH of 12.00, calculate the mass of CH3NH2
that was dissolved to produce the solution.
Answers:
1. a) [H2][O2][H2O]net
b) [H2][O2][H2O]
c) [H2][O2][H2O]
d) [H2][O2][H2O]
2. P; T; [N2] or [H2] 3. a) closed system b) constant properties (P,c,T) c) rate(fwd) = rate (rev)
4. a) [A][B][C][D]net  b) [A][B][C][D] c) A][B][C][D]
5. 0.174 mol/L
6. a) 0.18 mol/L b) 0.41
7. Any of: Cl-/Br-/I-/ SO42-/OH-/PO43-/CO328. 1.52 x 10-11 9. TIP=1.2 x 10-12; ppt forms
10. 2.8 x 10-2 g
11. pH=12; pOH=2
+
-13
+
12. [H3O ] = 0.036 mol/L; [OH ] = 2.8x10 mol/L
13. [H3O ]=[OH-]=5.43 x 10-8 mol/L
14. 1.25 x 10-2 mol/L
15. 114g/mol 16. 5.09%
17. 1.4 x 10-4 18. 7.7x10-4 mol/L
19. 1.3 x 10-4 mol/L
20. 74.2 g
6
7
UNIT 6: ELECTROCHEMISTRY
1. If the silver half reaction (Ag+ + e-  Ag (s) ) was chosen as the standard for the half-cell potentials,
what would be the half-cell potential for Ni2+ + 2e-  Ni (s)?
2. Consider an electrochemical cell based on the following reaction:
3 Ca (s) + 2Al(NO3)  3 Ca(NO3)2 (aq) + 2 Al (s)
a) Predict the cell potential under standard conditions (Eocell).
b) If Ca(NO3)2 was added to the calcium half-cell, what would happen to the voltage?
c) If Na2S was added to the aluminum half-cell, what would happen to the voltage? (Al2S3 is insoluble)
3. Predict if the following reaction is spontaneous using Eo values:
MnO2 (s) + Cu(s) + 4 H+  Mn2+ + Cu Cu2+ 2 H2O (l)
4. Balance the following redox reaction using the oxidation number method:
I2
+
NO3-
+
H+ 
IO3- + NO
+ H2O
5. Balance the following using the half reaction method:
a) MnO4- + Sn2+ + H+ 
b) I- + Cr2O72- + H+ 
Mn2+ +
I2
+
Sn4+
Cr3+
+
+
H2O
H2O
6. Balance the following using oxidation numbers.
a) Zn2+ +
b) Cl2 
NO3-  Zn2+ + NH4+
Cl- + ClO3-
(acidic conditions)
(basic conditions)
7. Calculate the cell potential (voltage) for the following cell:
Zn (s) ∣ Zn2+ (0.001 M) ∥
Ag+ (0.01 M) ∣ Ag (s)
8. Although the voltage of an electrochemical cell is limited by the chemistry involved, higher voltages
can be achieved by connecting cells in series, where the cathode of one cell is attached to the anode of a
second cell. Consider a series of two cells constructed from these cells:
i) Ni(s) ∣ Ni2+ ∥ Sn2+ ∣ Sn (s)
ii) Zn (s) ∣ Zn2+ ∥
Cu2 ∣ Cu (s)
a) Label the cathode and anode in each half cell and show the direction electron move on the diagram.
b) Calculate the total voltage produced under standard conditions by this pair of cells.
9. Chrome plated objects are made in an electrolytic cell containing Cr3+(aq) ions. If as current of 25.5 A
is applied for 325 seconds, how many grams of Cr (s) would form on the object at the cathode?
7
8
10. An electrolytic cell can be used to produce aluminum metal from molten aluminum oxide, Al2O3 (l),
using two carbon electrodes and a DC power supply.
a) Draw the electrolytic cell and label the cathode, anode, direction of electron and ion movement. At
the anode, the following reaction occurs: 2 O2- + C (s)  CO2 (g) + 4eb) Write the two half reactions.
c) Write the balanced redox reaction.
Answers:
1. -1.05 V
2. a) Eocell = +1.21 V b) decrease c) decrease
3. Eo = +0.88V  spontaneous rxn
4. 3,10,4  6,10,2
4. a) 2,5,16  2,5,8 b)6,1,14  3,2,7 6. a) 4,1,10 4,1,3 b) 3,6  5,1,3
7. 1.53 V
8. 15.5 V
9. 1.49 g
10. c) 4 Al3+ + 6 O2- + 3C (s)  4 Al (s) + 3CO2 (g)
CONSTANTS:
𝑁𝐴 = 6.022 × 1023
𝑀𝑉 = 22.4
𝑝𝑎𝑟𝑡𝑖𝑐𝑙𝑒𝑠
ℎ = 6.63 × 10−37 𝑘𝐽 ∙ 𝑠
𝑚𝑜𝑙
𝐿
𝐾𝑤 = 1.00 × 10−14 (𝑎𝑡 25℃)
𝑚𝑜𝑙
𝑐 = 3.00 × 108 𝑚⁄𝑠
𝑅 = 8.314
𝑐𝑤 = 4.184
𝑘𝑃𝑎∙𝐿
𝐽
𝑔∙℃
1 𝐹 = 1 𝑚𝑜𝑙 𝑒 − = 96500𝐶
𝑚𝑜𝑙∙𝐾
𝐷𝑤 = 1.00 𝑔⁄𝑚𝐿
8
9
FORMULAS:
𝑃1 𝑉1
𝑃𝑉 = 𝑛𝑅𝑇
𝐷=
𝑇1
𝑚
𝑃2 𝑉2
𝑛
𝑐=𝑉
𝑇2
𝑚
𝑉
𝐸 = ℎ𝑓
𝐸𝑛 =
=
−1312 𝑘𝐽/𝑚𝑜𝑙
𝑚𝑠𝑜𝑙𝑢𝑡𝑒
𝑛=𝑀
% 𝑏𝑦 𝑚𝑎𝑠𝑠 = 𝑚
𝐸 = ℎ𝑓𝑁𝐴
𝜆=𝑓
𝑠𝑜𝑙𝑢𝑡𝑖𝑜𝑛
𝑐
𝐸𝑡𝑟𝑎𝑛𝑠𝑖𝑡𝑖𝑜𝑛 = (
𝑛2
𝑐1 𝑉1 = 𝑐2 𝑉2
−1312 𝑘𝐽/𝑚𝑜𝑙
2
𝑛𝑓
)−(
× 100
Δ𝐸𝑁 = 𝐸𝑁2 − 𝐸𝑁1
−1312 𝑘𝐽/𝑚𝑜𝑙
𝑛𝑖2
)
𝑞
Δ𝐻 = 𝐻𝑝𝑟𝑜𝑑𝑢𝑐𝑡𝑠 − 𝐻𝑟𝑒𝑎𝑐𝑡𝑎𝑛𝑡𝑠
Δ𝐻 = ± 𝑛
∆𝐻 = Σ(𝑛Δ𝐻form (products)) − Σ(nΔHform (reactants))
Δ𝐻 = Σ𝐻𝑏𝑜𝑛𝑑𝑠 𝑏𝑟𝑜𝑘𝑒𝑛 − Σ𝐻𝑏𝑜𝑛𝑑𝑠 𝑓𝑜𝑟𝑚𝑒𝑑
𝑞 = 𝑚𝑐∆𝑇
∆𝐻 =
𝐸 = 𝑚𝑐 2
𝑁=
𝐴𝑣𝑔 𝑅𝑥𝑛 𝑅𝑎𝑡𝑒 =
𝑟𝑎𝑡𝑒 =
𝑞𝑟𝑥𝑛
𝑛
𝑁𝑜
2𝑛
=
−𝑞𝑠𝑢𝑟𝑟
or
𝑛
𝑚𝑟𝑒𝑚𝑎𝑖𝑛𝑖𝑛𝑔 =
𝑎𝑚𝑜𝑢𝑛𝑡 𝑜𝑓 𝑟𝑒𝑎𝑐𝑡𝑎𝑛𝑡 𝑐𝑜𝑛𝑠𝑢𝑚𝑒𝑑
∆𝑐
𝑡
𝑛=𝑡
2𝑛
½
𝐴𝑣𝑔 𝑅𝑥𝑛 𝑅𝑎𝑡𝑒 =
𝑡𝑖𝑚𝑒
𝐴1
𝑟 = 𝑘[𝑋]𝑚 [𝑌]𝑛
∆𝑡
𝑚𝑜𝑟𝑖𝑔𝑖𝑛𝑎𝑙
𝐴2
𝑎𝑚𝑜𝑢𝑛𝑡 𝑜𝑓 𝑝𝑟𝑜𝑑𝑢𝑐𝑡 𝑝𝑟𝑜𝑑𝑢𝑐𝑒𝑑
𝑟
𝑡𝑖𝑚𝑒
𝐴1
= 𝑟1
𝐴2
2
Δ𝐻 = 𝐻𝑝𝑟𝑜𝑑𝑢𝑐𝑡𝑠 − 𝐻𝑟𝑒𝑎𝑐𝑡𝑎𝑛𝑡𝑠
Δ𝑆 = 𝑆𝑝𝑟𝑜𝑑𝑢𝑐𝑡𝑠 − 𝑆𝑟𝑒𝑎𝑐𝑡𝑎𝑛𝑡𝑠
[𝐶]𝑐 [𝐷]𝑑
𝐾 = [𝐴]𝑎[𝐵]𝑏
𝐾𝑎 =
[𝐻3 𝑂 + ][𝑋 − ]
[𝐻𝑋]
Δ𝐺 = Δ𝐻 − 𝑇Δ𝑆
𝐾𝑤 = [𝐻3 𝑂+ ][𝑂𝐻 − ]
𝐾𝑏 =
𝐾𝑤 = 𝐾𝑎 𝐾𝑏
[𝑂𝐻 − ][𝐻𝑋]
[𝑋 − ]
𝑝𝐻 = −𝑙𝑜𝑔[𝐻3 𝑂+ ]
𝑝𝑂𝐻 = −𝑙𝑜𝑔[𝑂𝐻 − ]
[𝐻3 𝑂+ ] = 10−𝑝𝐻
[𝑂𝐻 − ] = 10−𝑝𝑂𝐻
𝑝𝐻 + 𝑝𝑂𝐻 = 14
𝑜
𝑜
𝑜
𝐸𝑐𝑒𝑙𝑙
= 𝐸𝑟𝑒𝑑
+ 𝐸𝑜𝑥𝑖𝑑
𝑛
𝐾 = 100.059
𝑜
𝐸𝑐𝑒𝑙𝑙 = 𝐸𝑐𝑒𝑙𝑙
−
𝑜
𝐸𝑐𝑒𝑙𝑙
𝐼=
9
𝑄
𝑡
0.059
𝑛
𝑡
= 𝑡2
𝑙𝑜𝑔𝐾 ∗
1
10
10
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