Review for Bonding Test (Jan 2015) – Remember to read Ch. 7 + 8 some on hydrogen bonding
(ch12) to review (and see pictures of) these concepts.
Especially chapter 7 section 2 (pages 210-217), chapter 8 section 1 (pages 240-245), chapter 8 section 3 (pages 253260), chapter 8 section 4 (pages 261-264), and chapter 12 section 2 (pages 411-414, especially page 413).
(Review chapter 10 section 4 (pages 341-350). For empirical and molecular formulas)
Know the following concepts VERY WELL:
Ionic vs covalent
Polar vs Nonpolar
Electronegativity
Lewis Dot Structures and VSEPR shapes
Bonding
Given two molecules CH2Cl2 and CH4, how can one be nonpolar and the other polar? Which is nonpolar?
Bonding orbitals used & shape:
Match with its shape:
Nomeclature – name the molecule:
Lewis Dot Model:
s
shape: ___Line_____
H2
___________________
________
s2
shape: _linear_______
H2O
___________________
________
sp2
shape: ________
CH4
___________________
________
sp3
shape: ________
BeF2
___________________
________
p3
shape: ________
BH3
___________________
________
p2
shape: ________
PH3
___________________
________
p
shape: __Line______
Cl2
___________________
________
1.
2.
3.
4.
A covalent bond is created when _______(#) electrons are shared.
A triple covalent bonds has _______(#) electrons shared.
Ammonia (NH3) makes a_____________shape and is ___________(polar or non-polar).
Oxygen has ________(#) pairs of unbonding electrons in a water molecule, these electrons are called ________
pairs.
Be able to Draw Lewis Dot Structures for Ionic Compounds, Molecular Compounds and polyatomic ions
Draw Lewis Dot Structures, give their VSEPR shapes and determine if the molecules are polar.
BeCl2
NI3
ClO3-
HClO3
Be able to solve empirical and molecular formula problems
5. A compound with the following composition has a molar mass of 60.10g/mol: 39.97% carbon; 13.41%
hydrogen; 46.62% nitrogen. First find the empirical formula then find the molecular formula.
6. Naphthalene is a carbon and hydrogen containing compound often used in moth balls. The empirical
formula is C5H4 and its molar mass is 128.16g/mol. Find the molecular formula.
7. Water only has a mass of 18 g/mol and is a liquid at room temperature; N 2 and O2 have a greater molar
mass (28 g/ mol and 32 g/ mol). Why is water a liquid and the others gases ?
Vocabulary – know definitions and be able to use in the context of a question:
Covalent Bond –
Ionic Bond –
Electron Dot Structures –
Octet Rule –
Electronegativity –
VSEPR
Selected Answers: 1. Two
2. Six
3. Pyramidal, polar
4. Two, lone pairs
5. C2H8N2
6. C10H8
Review for Bonding Test – SAMPLE ANSWERS
Assigned readings: p.240-243, p.253-257, p. 261-270
Chapter 210-215
Know the following concepts VERY WELL:
Why and how atoms ionize To complete an octet or to have the electron configuration of a Nobel gas
Ionic vs covalent Ionic give and take to for ions (metal positive cations, negative non-metal anions, covalent SHARE to
complete an octet
Polar vs Nonpolar Polar means lopsided shape (or pointable); Non-polar are balanced or non-lopsided
Water is polar oils are non-polar
Electronegativity if the electronegativity on one element is a lot more than the other the compound forms ions (or is
“polared apart”)
Given two molecules CH2Cl2 and CH4, how can one be nonpolar and the other polar? Which is nonpolar?
CH2Cl2 is polar, the chlorine attracts the electrons in bonds better than the hydrogen; CH4 is not lopsided (nonpolar) the
hydrogen are distributed evenly around the carbon center.
Bonding orbitals used & shape:
Match with its shape: Nomeclature – name the molecule: Electron Dot Model:
s
shape: ___Line_____
H2
s2
shape: _linear_______
H2O
_water or dihydrogen monoxide_
________
sp2
shape: trigonal planer_
CH4
__methane or carbon tetra hydride)_
________
sp3
shape: _tetrahedral___
BeF2
__berylium fluoride___
________
p3
shape: _pyramidal___
BH3
___Boron hydride_____
________
p2
shape: _bent line____
PH3
__Phosphorus tri hydride__
________
p
shape: __Line______
Cl2
__Chlorine__________
________
1.
2.
3.
4.
___hydrogen_____
________
A covalent bond is created when _______(#) electrons are shared.
A triple covalent bonds has _______(#) electrons shared.
Ammonia (NH3) makes a_____________shape and is ___________(polar or non-polar).
Oxygen has ________(#) pairs of unbonding electrons in a water molecule, these electrons are called ________
pairs.
Vocabulary – know definitions and be able to use in the context of a question:
Covalent Bond –
Ionic Bond –
Electron Dot Structures –
Octet Rule –
Electronegativity –
VSPER
Selected Answers: 1. Two
2. Six
3. Pyramidal, polar
4. Two, lone pairs