Chemistry 20: Module 1: Lesson 2
1
Assignment
MODULE 1: LESSON 2 ASSIGNMENT
This Module 1: Lesson 2 Assignment is worth 60 marks. The value of each assignment
and each question is stated in the left margin.
(60 Marks)
Lesson 2 Assignment: Elements and Ions
(4 marks)
1.
Write the symbol corresponding to each of the following theoretical descriptions.
a. 8 protons and 10 electrons
b. 18 electrons and a net charge of 3+
c.
2 electrons and 2 protons
d. 33 protons and 3 extra electrons
(1 mark)
2.
Cesium, mercury, and radium are examples of
A.
B.
C.
D.
metals
non-metals
semi-metals
compounds
Answer:
(1 mark)
3.
Neon, argon, and krypton are part of a group of elements called
A.
B.
C.
D.
alkali metals
noble gases
halogens
alkaline-earth metals
Answer:
Chemistry 20: Module 1: Lesson 2
2
Assignment
Use the following diagram to answer questions 5 to 7.
(1 mark)
5.
What is the atomic number of the element?
A.
B.
C.
D.
17
18
35
36
Answer:
(1 mark)
6.
What is the atomic mass of the element? Express your answer to two decimal
places.
Answer:
(1 mark)
7.
Which element is it?
A.
B.
C.
D.
argon
bromine
chlorine
magnesium
Answer:
Chemistry 20: Module 1: Lesson 2
(6 marks)
(16 marks)
8.
9.
3
Assignment
Draw condensed versions of the following ions.
a.
fluoride ion
b.
calcium ion
c.
nitride ion
Complete the following table.
Atom or
Ion Name
Symbol
Number of
Protons
Number of
Electrons
56
54
Charge
Cs+
lost 1
34
cadmium
ion
Number of
Electrons
Lost or
Gained
2–
46
Chemistry 20: Module 1: Lesson 2
4
Assignment
MODULE 1: LESSON 3 ASSIGNMENT
This Module 1: Lesson 3 Assignment is worth 50 marks. The value of each assignment
and each question is stated in the left margin.
(22 Marks)
Lesson 3 Assignment: Ionic Compounds
(10 marks)
1.
Fill in the table with the required information. The first one is done for you.
Atoms Combined
Formula of Ions
Involved
Chemical
Formula
Name of
Compound
Na and Cl
Na+ and Cl–
NaCl
sodium chloride
Ca and Cl
K and Br
Fe3+ and OH–
aluminium sulfide
Nickel (II) cyanide
Ga2(SO4)3 • 18H2O
Cu3N2
Mg2+ and O2–
Al and O
AuBO3
(12 marks)
2.
Complete the following table.
Element
Electronegativity
Group
Number
1.3
Number of
Valence
Electrons
Number of
Bonding
Electrons
2
3.2
1.6
13
0.9
1
1.9
2.2
4
1
Number of
Lone Pairs
of
Electrons
Chemistry 20: Module 1: Lesson 2
5
Assignment
MODULE 1: LESSON 4 ASSIGNMENT
This Module 1: Lesson 4 Assignment is worth 22 marks. The value of each assignment
and each question is stated in the left margin.
(22 Marks)
Lesson 4 Assignment: Molecular Elements and Compounds
(6 marks)
1.
Provide the name for each of the following compounds.
a. CO2(g)
b. NH3(g)
c.
P4O6(s)
d. Cl2(g)
e. H2O2(l)
f.
(6 marks)
2.
NI3(s)
Provide the correct chemical formula for each of the following compounds.
a. bromine
b. sulfur trioxide
c.
sulfur
d. methanol
e. phosphorus
f.
(10 marks)
3.
sucrose
Use the periodic table to calculate the electronegativity difference for each pair of
elements. Determine whether each compound is non-polar covalent, polar
covalent, or ionic.
a. the bond between Mg and F atoms in MgF2
b. the bond between H and S atoms in H2S
c.
the bond between Al and O atoms in Al2O3
d. the bond between Br atoms in Br2
e. the bond between N and H atoms in NH3
Chemistry 20: Module 1: Lesson 2
6
Assignment
MODULE 2: LESSON 1 ASSIGNMENT
Lesson 1 Assignment: Bonding Theory and Lewis Formulas
1.
Draw the Lewis symbols for the first three elements of group 2 on the periodic
table. How are these elements similar?
Answer:
2.
Draw the Lewis symbols for the first three elements of group 17 on the periodic
table. How are these elements similar?
Answer:
3.
Draw the Lewis formula and structural diagram for the following molecular
elements.
a.
Iodine (I2)
Answer:
b.
Nitrogen (N2)
Answer:
Chemistry 20: Module 1: Lesson 2
4.
7
Assignment
Draw the Lewis formula and structural diagram for the following molecular
compounds.
a.
hydrogen sulfide, H2S
Answer:
b.
hydrogen cyanide, HCN
Answer:
c.
methanol, CH3OH
Answer:
5.
Identify the central atoms for each of the compounds drawn in question 4 above.
Answer:
Chemistry 20: Module 1: Lesson 2
8
Assignment
MODULE 2: LESSON 2 ASSIGNMENT
Lesson 2 Assignment: Molecular Shapes and VSEPR Theory
1.
For each compound, draw the Lewis formula and stereochemical formula. Identify
its VSEPR geometry.
a.
BeCl2
Answer:
b.
PF3
Answer:
c.
BBr3
Answer:
f.
CH2O
Answer:
g.
CS2
Answer:
Chemistry 20: Module 1: Lesson 2
9
Assignment
LESSON 2— MOLECULAR SHAPES AND VSEPR THEORY
Representing Atoms Using Models
When using models to represent atoms, lone pairs of electrons tend not to be represented. In
molecular model kits the location of bonding electrons is indicated by holes. Since bonding electrons
(bond pairs) are used to form covalent bonds between atoms, their location is identified by the
connections between atoms. Using the information below, you will be able to identify where bond
pairs can develop for a variety of non-metallic elements.
Element
Lewis Formula
Lone
Pairs
Bonding Attachment Location of Attachment Points
Electrons
Points
Hydrogen
0
1
1
Beryllium
0
2
2
Boron
0
3
3
Carbon
0
4
4
Chemistry 20: Module 1: Lesson 2
10
Assignment
Nitrogen
1
3
3
Oxygen
2
2
2
Halogen
(fluorine,
chlorine,
iodine,
bromine)
3
1
1
Chemistry 20: Module 1: Lesson 2
11
Assignment
LESSON 2 — MOLECULAR SHAPES AND VSEPR THEORY
Try This: Using VSEPR Theory to Predict Molecular Shape
In Chemistry 20 molecule shape focuses on the arrangement of atoms around central atoms. As you
will learn in this activity, the presence of bond pairs as well as lone pairs of electrons influences a
molecule’s shape.
To complete this activity you will need to be familiar with the following electron pair arrangements and
the shapes that result.
Trigonal
Linear
Angular
Tetrahedral
Trigonal Planar
Pyramidal
Complete the following table as you work through the activity.
Molecule
beryllium
dihydride, BeH2
boron trihydride,
BH3
methane, CH4
ammonia, NH3
water, H2O
Lewis
Formula
Bond
Pairs
Lone
Pairs
Total
Pairs
Electron Pair
Arrangement
(shape)
Stereochemical
Formula (3-D
representation)
Chemistry 20: Module 1: Lesson 2
hydrogen
chloride, HCl
oxygen, O2
nitrogen, N2
carbon dioxide,
CO2
12
Assignment
Chemistry 20: Module 1: Lesson 2
13
Assignment
MODULE 2: LESSON 3 ASSIGNMENT
Lesson 3 Assignment: Molecular Polarity
Lab: Evidence for Polar Molecules
Part 1: Pre-Lab
1. Draw stereochemical formulas for the following molecules. (6 marks)
Substance
Water
Pentane
Ethanol
Chemical
Formula
H2O
C5H12
C2H5OH
Methanol
Don’t do
CH3OH
Don’t do
Structural
Formula
Don’t do
Stereochemical
Formula
DO NOT DO
DO NOT DO
2. Complete a hypothesis to predict which substances are polar. Justify your selections.
(4 marks)
Answer:
Chemistry 20: Module 1: Lesson 2
14
Assignment
MODULE 2: LESSON 4 ASSIGNMENT
Lesson 4 Assignment: Intermolecular Forces
Part 2
2. Complete Lab Exercise 3. A, "Boiling Points and Intermolecular Forces," on page 110
of your textbook.
a. Place a copy of your graph here. (10 marks)
Chemistry 20: Module 1: Lesson 2
15
Assignment
b. Which compounds do not fit the pattern for the rest in their group? Why? (3 marks)
Answer:
(10 marks)
4.
Complete the following table. The first row has been done for you.
Molecule
HBr
Structural
Shape
Polarity
Types of
Intermolecular
linear
polar
dipole-dipole
NF3
GeH4
NI3
CF4
HF
6.
Given the gases methane, CH4(g), and sulfur dioxide, SO2(g), predict which of the
two will be more soluble in water. Explain your answer. (2 marks)
Answer:
Chemistry 20: Module 1: Lesson 2
16
Assignment
Unit 1 Review Assignment: (133)
Please submit all your work when you have completed this assignment. Show all work wherever
necessary.
1. Complete energy level diagrams and the table for the following elements: (10 marks)
Name
Magnesium
Oxygen
Phosphorus
Calcium
Hydrogen
Energy Level Diagram
Number of
protons
Number of
electrons
Number of
valence
electrons
Number
of
neutrons
Chemistry 20: Module 1: Lesson 2
17
Assignment
2. Complete energy level diagrams and the table for the following ions: (8 marks)
Name
Energy Level Diagram
Number of
protons
Number of
electrons
Number of
valence
electrons
Number
of
neutrons
Hydrogen ion
Oxide
Chlorine ion
Potassium ion
3. What is the atomic number equal to for elements? (1 mark)
4. What subatomic particle can you find the quantity of using atomic mass? (1 mark)
5. In an element, the number of protons equals the number of electrons which allows it to have no
net charge. In a cation, there are __________(more/less) electrons than protons, giving it a
___________(positive/negative) charge. These are most likely ___________
(metals/nonmetals) on your periodic table. In a anion, there are __________(more/less)
electrons than protons, giving it a ___________(positive/negative) charge. These are most
likely ___________ (metals/nonmetals) on your periodic table. (6 marks)
Chemistry 20: Module 1: Lesson 2
18
Assignment
6. Complete the following table for ionic compounds, molecular compounds and elements. (18)
Ionic/
Molecular/
Element
Ionic
Name
Formula
IF Ionic, state if soluble
in water.
Sodium Chloride
NaCl
aq
Carbon monoxide
H2SO4
Iron(III)oxide
CuSO4
Sulphur
Methane
Methanol
Mg(OH)2
KMnO4
If you still require extra practice on naming, review chapter 1 in your Nelson textbook or contact your
teacher for additional resources.
7. Complete the following table: (4)
Ionic,
Molecular,
Or Acid
(I,M,A)
Name
Chemical
Formula
Potassium iodide
C3H8(g)
KMnO4(s)
Copper(II)sulfate
pentahydrate
Na2CO3(s)
Fe2O3(s)
Ammonium sulfate
C2H5OH(l)
Nitrogen tribromide
HF(aq)
Johnny was a chemist’s son,
But Johnny is no more…
What Johnny thought was H2O,
Was H2SO4.
Chemistry 20: Module 1: Lesson 2
19
8. Briefly describe the Kinetic Molecular Theory (2 marks)
9. Balance these equations! (15 marks)
1) ____ AlBr3 + ____ K  ____ KBr + ____ Al
2) ____ FeO + ____ PdF2  ____ FeF2 + ____ PdO
3) ____ P4 + ____ Br2  ____ PBr3
4) ____ LiCl + ____ Br2  ____ LiBr + ____ Cl2
5) ____ PbBr2 + ____ HCl  ____ HBr + ____ PbCl2
6) ____ CoBr3 + ____ CaSO4  ____ CaBr2 + ____ Co2(SO4)3
7) ____ Na3P + ____ CaF2  ____ NaF + ____ Ca3P2
8) ____ Mn + ____ HI  ____ H2 + ____ MnI3
9) ____ Li3PO4 + ____ NaBr  ____ Na3PO4 + ____ LiBr
10) ____ CaF2 + ____ Li2SO4  ____ CaSO4 + ____ LiF
11) ____ HBr + ____ Mg(OH)2  ____ MgBr2 + ____ H2O
12) ____ LiNO3 + ____ CaBr2  ____ Ca(NO3)2 + ____ LiBr
13) ____ AgNO3 + ____ Li  ____ LiNO3 + ____ Ag
14) ____ Si(OH)4 + ____ NaBr  ____ SiBr4 + ____ NaOH
15) ____ NaCN + ____ CuCO3  ____ Na2CO3 + ____ Cu(CN)2
Assignment
Chemistry 20: Module 1: Lesson 2
20
Assignment
10. Fill in the following table (18)
Chemical
Formula
Lewis
Structure
Stereochemical
And VSPER
shape
Intramolecular
forces
Intermolecular
Forces
Solubility
in Water
(Y/N)
CH2O
BBr3
OF2
SiH4
HCN
HNO
11. When the energy from temperature is reduced (temperature is reduced), what causes
carbon monoxide to go from a gas to a liquid? – 2 marks
Chemistry 20: Module 1: Lesson 2
21
Assignment
12. Which of the following hydrocarbons would have the higher boiling point (explain): CH 3OH
or C2H5OH? -2 marks
13. Identify the type of substance that is material X from the following properties and justify
your answer. – 2 marks
Melting Point
Boiling Point
Conductivity
Solubility in water
Material X
750oC
2250oC
No
No
14. Identify the following bonds within (intramolecular) the molecule or compound as:
a. non polar covalent
b. polar covalent
c. ionic
1. C3H8
2. LiF
3. CO2
15. Which statement below is true for the Aluminum atom:
a. aluminum has one bonding pair of electrons
b. aluminum has three bonding pairs of electrons and one lone pair
c. aluminum has only three bonding electrons
d. aluminum has one lone pair and three bonding electrons
Chemistry 20: Module 1: Lesson 2
22
Assignment
16. Which statement below is false for the Phosphorus atom:
a. Phosphorus has one lone pair.
b. Phosphorus has 5 valence electrons.
c. Phosphorus bonds with three others to form its basic molecular compound.
d. Phosphorus has three bonding pairs.
17. Which statement is true for the nitrogen molecule:
a. It has 3 bond pairs
b. It has 1 lone pair
c. It has 3 bonding electrons
d. It has 1 lone pair and 3 bonding electrons
18. Which statement is true for phosphorus trichloride:
a. It forms 3 weak bonds.
b. It does not dissolve in water.
c. It creates 3 covalent bonds.
d. It is ionic.
19. How many electrons are in the valence level of P?
a. 2
b. 3
c. 4
d. 5
20. How do the electronegativities compare on the periodic table within a period?
a. Electronegativities go up the further right you go.
b. Electronegativities go up the further left you go.
c. Electronegativities go down the further down you go.
d. Electronegativities go down the further up you go.
21. Which does NOT follow according to VSEPR theory:
a. Valence electrons are paired in a molecule or polyatomic ion.
b. Valence pairs repel each other electrostatically.
c. Atoms with greater electronegativity will have a stronger pull towards bonded
pairs of electrons.
d. The molecular shape is determined by the positions of the electron pairs when
they are a maximum distance apart.
Chemistry 20: Module 1: Lesson 2
23
Assignment
For questions 22-26 identify the correct electron pair arrangement according to the VSEPR
theory. Use the following data to solve these questions.
Electron pair arrangements
i. Linear
ii. Trigonal Planar
iii. V – Shaped
iv. Trigonal Pyramidal
v. Tetrahydral
22. CO2
23. NH3
24. BCl3
25. SiCl4
26. OCl2
27. Which type of bond has the most electronegative difference:
a. Hydrogen Bond
b. Polar Covalent Bond
c. Non-Polar Covalent Bond
d. Ionic Bond
28. Circle ALL the Intermolecular forces that are found within distilled water.
a. Hydrogen bonding
b. Dipole- Dipole
c. London Forces
d. Ionic Bonding
e. All of the above
29. “Doping” is the process of adding a tiny quantity (5 ppm) of a group 13 or 15 element to:
a. Make an ionic crystal conductive
b. Make a covalent network crystal conductive
c. Strengthen bonds within a crystal lattice
d. Increase melting point of a crystal
Chemistry 20: Module 1: Lesson 2
24
Assignment
Please be specific and use theories and scientific concepts discussed in class whenever
possible to support your answer.
30. Which element has: 2 bonding electrons, 2 lone pairs and 3 energy levels? (1)
31. Name and draw (using LDD) a compound with 3 bond pairs and 1 lone pair of
electrons. (2)
32. What kind of bond forms between oxygen atoms in an oxygen molecule (O2)? Be
specific. (1)
For questions 33-36, use Lewis Diagrams to draw the following. (4 marks)
33. [NH4]+
34. CH2O
35. CH3SH
36. HCN
37. Explain a process to determine whether an unknown liquid is polar or non polar? (2)
Chemistry 20: Module 1: Lesson 2
25
Assignment
38. Mechanics in a shop spill oil on a regular basis. Describe an environmentally safe
method of cleaning these spills and justify with your reasoning. (4)
39. Explain why chlorine gas (Cl2(g)) will not dissolve in water but would in hexane
(C6H14(l)). (3)
40. Explain the boiling points of the following hydrogen compounds with relation to each
other. Describe the similar forces and the difference in boiling points. (3)
Compound (at SATP)
CH4(g)
SiH4(g)
Electrons
10
18
Boiling Point (oC)
-164
-112
41. Describe the physical property that allows an insect to walk on top of water? (2)
Chemistry 20: Module 1: Lesson 2
26
Assignment
Use the table to answer questions 42
Unknown Chloride
Melting Point (oC)
Boiling Point (oC)
Solubility in water
Solubility in C6H6(l)
XCla
-75
53
very low
high
XClb
850
1480
high
very low
42. What type of bonding would be in each chloride listed (justify your answer)? (4)