Aristo Chemistry Book 3 Answer

HKDSE CHEMISTRY – A Modern View (Chemistry)
Coursebook 3
Suggested answers
Chapter 25 Simple molecular substances with non-octet structures and shapes of simple molecules
Page Number
Class Practice
1
Chapter Exercise
2
Chapter 26 Bond polarity
Class Practice
4
Chapter Exercise
5
Chapter 27 Intermolecular forces
Class Practice
7
Chapter Exercise
9
Chapter 28 Structures and properties of molecular crystals
Class Practice
11
Chapter Exercise
12
Part Exercise
14
Chapter 29 Chemical cells in daily life
Class Practice
17
Chapter Exercise
18
Chapter 30 Simple chemical cells
Class Practice
21
Chapter Exercise
22
Chapter 31 Redox reactions
Class Practice
24
Chapter Exercise
26
Chapter 32 Redox reactions in chemical cells
Class Practice
29
Chapter Exercise
30
Chapter 33 Electrolysis
Class Practice
32
Chapter Exercise
33
Chapter 34 Importance of redox reactions in modern ways of living
Class Practice
36
Chapter Exercise
37
Part Exercise
39
Chapter 35 Energy changes in chemical reactions
Class Practice
42
Chapter Exercise
43
Chapter 36 Standard enthalpy change of combustion, neutralization, solution and formation
Class Practice
44
Chapter Exercise
46
Chapter 37 Hess’s Law
Class Practice
48
Chapter Exercise
51
Part Exercise
53

Chapter 25 Simple molecular substances with non-octet structures and shapes of simple molecules

Class Practice

A25.1
(a) BCl3 NCl3 IF3
(b) BCl3. The central boron atom has only six outermost shell electrons. IF3. The central iodine atom has 10 outermost shell electrons.

A25.2
Molecule
No. of electron pairs
Spatial arrangement of electron pairs
No. of lone pairs
No. of bond pairs
Shape
CH4
4
Tetrahedral
0
4
Tetrahedral
NH3
4
Tetrahedral
1
3
Trigonal pyramidal
H2O
4
Tetrahedral
2
2
V-shaped

Chapter 25 Simple molecular substances with non-octet structures and shapes of simple molecules

Chapter Exercise

1. eight
2. eight
3. six
4. 10
5. 12
6. non-octet
7. linear, 180°
8. trigonal planar, 120°
9. tetrahedral, 109.5°
10. trigonal bipyramidal, 90°,