Section A
Question 1:
Give one word or term for the descriptions below. Write only the correct term
next to the corresponding number (1.1-1.5)
1.1
The reaction that takes place between an acid and a base
(1)
1.2
Give the name of the product formed when carbon reacts with oxygen in a
ratio 1:2
(1)
1.3
The process in which metal is broken down
(1)
1.4
Two or more different atoms bonded together
(1)
1.5
Electrons found in the highest energy level
(1)
[5]
Question 2:
There are four possible answers given the questions below. Write only the correct
letter (A-D) next to the corresponding number (2.1-2.5)
2.1
The common name for this compound: Na Cl
A)
Sea salt
C)
Ocean view
B)
Sodium chloride
D)
Table salt
2.2
When non-metals share electrons, the bond is called …
A)
Covalent
C)
Metallic
B)
Ionic
D)
Constructive
1
(2)
(2)
2.3
Choose the correct combination:
Protons are …
A)
Positively charged and found around the nucleus
B)
Negatively charged and found around the nucleus
C)
Positively charged and found inside the nucleus
D)
Negatively charged and found inside the nucleus
2.4
When a substance reacts with oxygen, the reaction is known as …
A)
Combustion
C)
Indication
B)
Neutralization
D)
Chemical
2.5
Study the reaction below and answer the question that follows:
HCl +
CaCO3
→
CaCl2
+
(2)
CO2 +
(2)
H2O
How many Chlorine atoms are present in the product?
A)
1
C)
3
B)
2
D)
4
(2)
[10]
2
Question 3:
Match the information in Column A with the correct answer in Column B. Write
only the correct letter (A-H) next to the corresponding number (3.1-3.5)
3.1
3.2
3.3
3.4
3.5
COLUMN A
Chemical name: NaOH
Shampoo
CO2 and SO2
Galvanising
Diatomic element
COLUMN B
Basic substance
Prevent rust
H2
Acidic substance
Na
Causes acid rain
Sodium Hydroxide
Causes rust
ABCDEFGH-
[5x1= 5]
Section A /20/
Section B:
Question 4:
Refer to the periodic table given to answer the questions that follow
4.1
Complete the table by only writing the correct answer next to the
corresponding letter (a-h)
Name
(a)
( c)
Nitrogen
Iron
Symbol
Atomic number
Mn
25
11
(d)
N
(e)
26
(g)
3
Standard
Atomic Mass
(b)
23
(f)
(h)
(8 x ½ = 4)
4.2
Give the chemical symbol of any two (2) metals
(2)
4.3
Give the chemical symbol of any two (2) non- metals
(2)
4.4
What are the elements in group 2 called?
(1)
4.5
What are the elements in group 17 called?
(1)
4.6
Study the figure below and answer the questions that follow:
27
Co
59
4.6.1 How many protons does this element have?
(1)
4.6.2 Name this element?
(1)
4.6.3 How many neutrons does this element have?
(1)
[13]
Question 5:
Chemical Formula:
5.1.1 How many atoms of each element are present in the compound below?
a)
4 Al2O3
(2)
b)
12 NaCl
(2)
c)
6NH3
(2)
5.1.2 Now give the Chemical Name for each of the compounds above
4
(3x1=3)
5.2
Show how the electrons are structured (electron configuration) in the
following atoms
[Hint: show the protons (+), neutrons (o) and electrons (e-)]
a)
Sulfur
(3)
b)
Potassium
(3)
5.3
Give the names of two (2) diatomic elements
(2)
[17]
Question 6:
Chemical Equations
6.1
6.2
Write the following chemical equations out in words:
a)
Zn
+
b)
HCl +
Cl2
→
MgO →
ZnCl
(2)
MgCl2
+
H2O
(2)
A grade 9 class had to do a practical, by reacting metals with oxygen. Two
metals were used: Iron and Magnesium.
6.2.1 What do we call the product when a metal react with oxygen
(1)
6.2.2 Magnesium was used in this practical:
a)
What was the AIM of this investigation?
(2)
b)
What was the colour of the flame of burning magnesium?
(1)
c)
d)
Name the product formed
What was the colour of the product?
(1)
(1)
e)
Write out a word equation for this reaction
(2)
f)
Balance the following equation:
Mg
+
→
O2
5
MgO
(3)
6.3
Balance the following chemical equations:
a)
Al
b)
HCl +
Li2O →
c)
Cu
O2
6.4
Complete the table, by redrawing it on your answer sheet
+
+
O2
Name of
substance
Iron
Carbon
(e)
→
→
Al2O3
(3)
LiCl +
H2O
CuO
(3)
(3)
Metal / Nonmetal
(a)
( c)
Non-metal
Colour of flame
(b)
(d)
Bright blue
Name of
product formed
when reacted
with oxygen
Iron oxide
Carbon dioxide
(f)
(6x1=6)
[30]
Question 7:
Acids and Bases
7.1
Tabulate three differences between Acids and Bases
(3x2=6)
7.2
State what colour the Universal Indicator would be if the pH of a substance
was:
7.2.1)
3
(1)
7.2.2)
7
(1)
7.2.3)
9
(1)
7.3
Name one Natural Indicator
(1)
[10]
6
Question 8:
Formation of Rust
Rust is an iron oxide, usually red oxide formed by the
redox reaction of iron and oxygen in the presence of
water or air moisture. Several forms of rust are
distinguishable visually and by spectroscopy, and form
under different circumstances.[1] Rust consists of hydrated
iron(III) oxides Fe2O3·nH2O and iron(III) oxidehydroxide (FeO(OH), Fe(OH)3).
Given sufficient time, oxygen, and water, any iron mass
will eventually convert entirely to rust and disintegrate.
Surface rust is flaky and friable, and provides no
protection to the underlying iron, unlike the formation of
patina on copper surfaces. Rusting is the common term
for corrosion of iron and its alloys, such as steel. Many
other metals undergo equivalent corrosion, but the
resulting oxides are not commonly called rust.
Other forms of rust exist, like the result of reactions
between iron and chloride in an environment deprived of
oxygen – rebar used in underwater concrete pillars is an
example – which generates green rust.
8.1
Name four (4) ways of preventing rust
(4)
8.2
Give the Chemical name for rust
(1)
8.3
What is the chemical symbol for rust?
(1)
8.4
Give a brief explanation of how rust forms
(3)
8.5
How are the forms of rust visually distinguished?
(1)
[10]
Section B /80/
7
Section A
Question 1:
1.1
Neutralisation reaction√
1.2
Carbon dioxide√
1.3
Corrosion√
1.4
Compounds√
1.5
Valence electrons√
[5]
Question 2:
2.1
D √√
2.2
A√√
2.3
C√√
2.4
A√√
2.5
B√√
[10]
Question 3:
3.1
G√
3.2
A√
3.3
F√
3.4
B√
3.5
C√
[5]
8
/20/
SECTION B
Question 4:
4.1
a- Manganese√
, b- 55√
c- Sodium√ , d- Na√
e- 7√ , f- 14√
g-Fe√ , h- 56√
[8x ½ =4]
4.2
Any 2 metals- must be chemical symbols√√
[2]
4.3
Any 2 non-metals, but must be chemical symbol√ √
[2]
4.4
Alkali earth metals√
[1]
4.5
Halogens√
[1]
4.6.1 27√
[1]
4.6.2 Cobalt√
[1]
4.6.3 59 – 27 = 32 √
[1]
[13]
Question 5:
5.1.1 a)
8 aluminium, 12 oxygen
b)
12 sodium, 12 chlorine
c)
6 nitrogen, 18 hydrogen
5.1.2 a)
Aluminium oxide
b)
Sodium chloride
c)
Ammonia
5.2 a)
b)
9
5.3
hydrogen, oxygen, nitrogen, chlorine. Fluorine, bromine, iodine (any 2)
[17]
Question 6:
6.1
a)
zinc + chlorine → zinc chloride
b)
hydrochloric acid + magnesium oxide → magnesium chloride + water (2)
6.2.1 a)
6.3
6.4
(2)
To see what happens when magnesium reacts with oxygen
(1)
b)
bright white
(1)
c)
magnesium oxide
(1)
d)
white
(1)
e)
magnesium + oxygen → magnesium oxide
(2)
f)
2Mg +
O2
→
2MgO
(3)
a)
4Al
3O2
→
2Al2O3
(3)
b)
2HCl +
Li2O →
2LiCl +
c)
2Cu +
O2
→
a-
metal,
b-
orange sparks
c-
non-metal, d-
yellow
e-
sulfur,
sulfur dioxide
+
f-
2CuO
H2O
(3)
(3)
(6x1=6)
[30]
10
Question 7:
7.1
(3x2=6)
ACIDS
Taste sour
pH 1-7
Non metal oxides
BASES
Caustic action on plants and animals
pH 8-14
Metal oxides
7.2.1
Red√
(1)
7.2.2
Green√
(1)
7.2.3
Dark Green√
(1)
7.3
Red cabbage, beetroot, red onion, turmeric (any 1) √ (1)
[10]
Question 8:
8.1
painting, √ galvanizing√, electroplating√, oil/ greasing√(4)
8.2
Iron oxide√ (1)
8.3
Fe2O3√ (1)
8.4
Iron on the object reacts with moisture in atmosphere√. The moisture
contains oxygen √And so iron reacts with oxygen in moisture√ (3)
8.5
by spectroscopy √ (1)
[10]
11