Year 10 General Science – Chemistry TRIAL Test – Answers 2013
Name: ANSWERS
Teacher: Mr. Hung
Section A— Multiple choice (20 marks) 1 mark each
Max = 70 marks
1
Which are properties of metals in general?
A Bad conductor of electricity and bad conductor of heat
B Bad conductor of electricity and good conductor of heat
C Good conductor of electricity and bad conductor of heat
D Good conductor of electricity and good conductor of heat
2
Which of these metals is liquid at room temperature?
A Beryllium
B Lithium
C Mercury
D Tungsten
3
C -----> A + B
The above reaction represents:
A decomposition
B combination
C precipitation
D combustion
4
Very active pure metals such as Lithium and Potassium are stored in _____ to
prevent reaction.
A Vinegar
B Alcohol
C Water
D Oil
5
In an atom, the positive particle is the:
A electron
B proton
C neutron
D nucleus
6
The proper chemical name for CO2 is:
A carbon dioxide
B carbonate
C carbon monoxide
D bicarbonate
Year 10 General Science – Chemistry TRIAL Test – Answers 2013
7
In the chemical reaction sodium + chlorine sodium chloride:
A sodium and chloride are the products
B sodium chloride is the product
C sodium, chlorine and sodium chloride are the products
D chloride is the product
8
When testing for hydrogen gas:
A you use the pop test
B you use some litmus paper and wait for a colour change
C you bubble the gas through limewater
D you smell the gas
9
Given that the symbol for aluminium is Al and the formula for the oxide ion
is O2, the formula for aluminium oxide is:
A Al2O3
B A13O
C Al3O2
D AlO.
10 An alloy is best described as:
A a country cooperating with another country
B a pure metal
C a mixture of a metal and an impurity added to improve it in some way
D a method of using electricity to extract a pure metal.
11 An atom has an electron configuration of 2,8,5. What group would it be in?
A 1
B 2
C 5
D 8
12 Which of the following metals can be found in a pure state in nature?
A Sodium
B Aluminium
C Copper
D Gold
13 Which are the Group 7 elements?
A inert gases
B alkali metals
C halogens
D alkaline earths
Year 10 General Science – Chemistry TRIAL Test – Answers 2013
14 What is the ions formed by Magnesium (electron configuration 2,8,2)?
A +1
B +2
C -2
D -3
15 The followings are the same in number to each other except?
A protons number
B neutrons number
C atomic number
D electron number
16 Sulphur has 16 electrons. When in its ground state, its electron configuration is:
A 8, 8
B 2, 8, 8
C 2, 8, 6
D 2, 2, 12
17 Which of the following statements about elements in group 1 is CORRECT?
A They form covalent compounds easily.
B All atoms in this group have 1 electrons in their outermost shell.
C Group 1 is known as the alkali metals.
D All group 1 elements are very reactive and need to be stored in oil.
18 What is the type of charge in the nucleus?
A positive
B negative
C neutral
D positive and neutral
1
1
1
1
19 Covalent bonding occurs between:
A compound and compound
B metal and non-metal atoms
C non-metal atoms and other non-metal atoms
D metal atoms and other metal atoms
1
20 Oxygen has an electron configuration 2,6. Use this information to determine the
most likely charge of oxide ions.
A +2
B -2
C +6
D -6
1
Year 10 General Science – Chemistry TRIAL Test – Answers 2013
Section B— Short answer (50 marks)
1
State the charge of:
(Answer Positive, negative or neutral)
a sodium ion - Positive
b chloride ion - Negative
c a magnesium atom - Neutral
d nucleus of an atom - Positive
e ionic compound, eg CuSO4 - Neutral
f covalent compound eg. NH3 - Neutral
2
Aluminium has an atomic number of 13.
a State how many protons would be in the nuclei of its atoms.
b State how many electrons would be in each of its atoms.
13
13
c State the electron configuration of its atoms when in their ground state. (2,8,3)
d Draw a electron shell diagram showing the
number of protons, neutrons and the electron
distribution.
e Predict the most likely charge of
aluminium ions.
+3
f The symbol for a sodium ion is Na+.
Use this format to state the symbol for
a aluminium ion. Al3+
3
Use the information given below to state the period and group number of the following
elements:
a Sodium (electron configuration 2,8,1). Period 3 and Group 1
b Nitrogen (electron configuration 2,5).
c Phosphorus (atomic number 15).
Period 2 and Group 5
(2,8,5) Period 3 and Group 5
d Neon (atomic number 10). (2,8) Period 2 and Group 8
4
Predict the most likely charges of any ions formed by the following elements.
a Chlorine (electron configuration 2,8,7) -1
b Potassium (electron configuration 2,8, 8,1).
c Sulphur (atomic number 16).
(2,8,6) -2
d Argon (atomic number 18)
(2,8,8)
+1
no ion formed
Year 10 General Science – Chemistry TRIAL Test – Answers 2013
5
List four ways in which the rate of a reaction may be increased.
1. Increase in temperature
2. Adding a catalyst
3. Increase the concentration of raw materials
4. Increase the surface area of raw materials
6
Define the structure of Sodium chloride in solid state.
Conventially NaCl has a crysttaline lattice structure with Cl ion surrounding the Na
positive ion.
On a larger scale NaCl comprises a 3-d structure, in which Na ions are conventially taken
at the corners of the cube.
This structure is very stable and a very high temperature is required to break it down (in
fact, 801 oC)
7
8
Identify the correct type of Bonding:
Choose from: covalent, metallic, ionic
Bonding
Term
ionic
charged atoms
metallic
electron “sea”
covalent
shared electrons
Give 3 differences between ionic and covalent compounds.
Ionic compound is formed between metals and non-metals whereas covalent compound is
formed with non-metals only
Ionic compound can dissolve in water and produces ions which con conduct electricity
Covalent compound has no ions so it can’t conduct electricity
Ionic compound has a high melting point, existing as solid most of the time whereas
covalent compound has a low melting point, existing as liquids or gases.
9
Write a balanced formula equation, including states, for the following reaction:
When aqueous solutions of lead(II) nitrate, Pb(NO3)2, and potassium Chloride, KCl, are
mixed, the white solid lead(II) chloride, PbCl2, forms from the solution, while the soluble
salt, potassium nitrate, KNO3, remains in solution.
Name this type of reaction.
Pb(NO3)2, + 2KCl ---- > PbCl2 + 2KNO3
Precipitation Reaction or Double Displacement Reaction
Year 10 General Science – Chemistry TRIAL Test – Answers 2013
10
11
Write the chemical formulae for the following compounds.
Name of ion
Symbol or
formula
lithium
calcium
hydroxide
aluminium
carbonate
oxide
nitrate
phosphate
Na+
Ca2+
OHAl3+
CO 23 O2–
NO3–
PO43-
a) Lithium hydroxide
b) Calcium Oxide
Na
Ca
CaO
c) Aluminium Phosphate AlPO4
d) Lithium Oxide
Li2O
e) Calcium Nitrate Ca(NO3)2
f) Aluminium Carbonate Al2(CO3)3
Here is an activity series:
K
LiOH
g)
Mg
Al
Zn
Fe Pb
Cu Ag
Au
a Which metal(s) would be most likely to: [ 7 marks ]
i the most inert (not reactive) Au
ii more reactive Calcium or Potassium Potassium
iii be stored in oil to avoid reaction Potassium and Sodium
iv be used to make jewellery Copper, Gold, Silver
v in ribbon form and burn in air to give a bright light Magnesium
vi displace Aluminium of Aluminium nitrate (Mg or Zn) Mg
vii best conductors of electricity Silver and Copper
b What types of metals can be found in the Galvanised Zinc nail?
Why Galvanisation is good? [ 2 marks ]
Nail is made of iron and coated by zinc = Galvanisation
to prevent rusting
c Which of the following reaction takes place? Explain your answer.
[ 2 marks ]
(A) 2AgNO3 + Cu ----> Cu(NO3)2 + 2Ag or
(B) Cu(NO3)2 + 2Ag -----> 2AgNO3 + Cu
Reaction (A) as copper is more reactive compared to silver