TOPIC 4.1 IONIC BONDING AND 4.2 COVALENT BONDING
Monday, April 30, 2012
Paper 1
____ 1.
____ 2.
Name: ____________________
Which compound contains ionic bonds?
A.
Magnesium bromide, MgBr2
B.
Dichloromethane, CH2Cl2
C.
Ethanoic acid, CH3COOH
D.
Silicon tetrachloride, SiCl4
An ionic bond would most likely form between the members of which of the following pairs?
I. Al and O
II. C and F
III. Na and Mg
A. I only
B. III only
C. I and II only
D. II and III only
____ 3.
____ 4.
____ 5.
Which one of the following compounds contains both ionic and covalent bonds?
A.
NH4Br (s)
B.
Na2O (s)
C.
HNO3 (l)
D.
N2O3 (g)
The number of electrons in the covalent bond between carbon and the oxygen atom in CO is:
A.
3
B.
4
C.
6
D.
8
How do bond length and bond strength change as the number of bonds between two atoms increases?
Bond length
Bond strength
A.
increases
increases
B.
increases
decreases
C.
decreases
increases
D.
decreases
decreases
____ 6.
____ 7.
____ 8.
____ 9.
Which one of the following molecules contains a triple bond?
A.
HCN
B.
C2H4
C.
H2CO
D.
O2
Which molecule has the largest bond angle?
A.
BF3
B.
CF4
C.
NF3
D.
OF2
How do the bond angles between hydrogen atoms and the central atom in H2O, NH3 and CH4 compare?
A.
The bond angles in H2O are less than those in NH3 which are less than those in CH4.
B.
The bond angles in CH4 are less than those in NH3 which are less than those in H2O.
C.
The bond angles in NH3 are less than those in CH4 which are less than those in H2O.
D.
The bond angles in these molecules are all equal.
Which molecule has polar bonds but is nonpolar?
A.
N2
B.
O3
C.
CO2
D.
NH3
____ 10. Which of the following bonds is the most polar?
A.
N−F
B.
P−F
C.
S−F
D.
Cl − F
____ 11. All of the following possess a dipole moment except
A.
HF
B.
SF2
C.
BF3
D.
CH2F2
TOPIC 4.1 IONIC BONDING AND 4.2 COVALENT BONDING
Monday, April 30, 2012
Paper 2
1.
Name: ____________________
The diagrams below represent the structures of iodine, sodium and sodium iodide.
A
(a)
(i)
B
C
Identify which of the structures (A, B and C) correspond to iodine, sodium and sodium iodide.
(1)
(ii)
State the type of bonding in each structure.
(3)
2.
(a)
Draw Lewis (electron dot) structures for CO2 and H2S showing all valence electrons.
(b)
State the shape of each molecule and explain your answer in terms of VSEPR theory.
(2)
CO2
H2S
(4)
(c)
State and explain whether each molecule is polar or non-polar.
(2)
SECTION B
Answer all parts of one question.
3.
(a)
Draw the Lewis structure of methanoic acid, HCOOH.
(1)
(b)
(c)
In methanoic acid, predict the bond angle around the
(i)
carbon atom.
(ii)
oxygen atom bonded to the hydrogen atom.
(2)
State and explain the relationship between the length and strength of the bonds between the carbon
atom and the two oxygen atoms in methanoic acid.
(3)
4.
(a)
An important compound of nitrogen is ammonia, NH3.
(i)
State the H–N–H bond angle in an ammonia molecule.
(1)
(ii)
Explain why the ammonia molecule is polar.
(1)
(b)
Ammonia reacts with hydrogen ions forming ammonium ions, NH4+.
(i)
State the H–N–H bond angle in an ammonium ion.
(1)
(ii)
Explain why the H–N–H bond angle of NH3 is different from the H–N–H bond angle of NH4+;
referring to both species in your answer.
(3)