Download ARISTO/WILSON Chemistry Series

ARISTO/WILSON Chemistry Series
CHEMISTRY – A Modern View
Exercise Book 1 (ANSWERS)
Chapter 5
1.
2.
3.
4.
Rocks and minerals
C
C
D
B
5. B
6.
(a)
A : calcium oxide (quicklime)
B : calcium hydroxide solution (limewater)
C : calcium carbonate
D : calcium chloride
(b)
(i)
When water is added to the white solid of calcium oxide, it turns into a
white suspension of calcium hydroxide (slaked lime), and gives out a
lot of heat at the same time. After filtration, a clear solution of calcium
hydroxide (limewater) is formed.
Calcium oxide + water  calcium hydroxide
(ii)
The clear colourless solution turns milky when carbon dioxide
is passing through it.
Calcium hydroxide (limewater) + hydrochloric acid  calcium chloride + water
(iii)
Effervescence occurs. The solid calcium carbonate dissolves to
give a colourless solution.
Calcium carbonate + hydrochloric acid  calcium chloride + carbon dioxide + water
(iv)
No observable change.
Calcium hydroxide + hydrochloric acid  calcium chloride + water
7.
(a) Ores
(b) Haematite
(c) After concentrating the haematite ore, the ore is heated with coke (carbon)
to a high temperature in a blast broken down into smaller pieces.
Iron(III) oxide + carbon  iron + carbon dioxide
8.
(a) Weathering rocks is the slow process (usually over thousands of years) in
which exposed rocks are broken down into smaller pieces.
(b) See textbook 1 , pages. 94 – 95
9.
Refer to your textbook !