CHEMISTRY
PRETEST
UNITS 3 and 4
DATA PAGE
Use the data tables below and the periodic table over the page to help you
answer the pre-test questions.
Table 1: Formulae and charge of selected ions:
Cations
Na sodium
Anions
OH hydroxide
NH4+ ammonium
Cl chloride
Ag+ silver
NO3 nitrate
Mg2+ magnesium
O2 oxide
Zn2+ zinc
SO42 sulfate
Cu2+ copper
CO32 carbonate
Pb2+ lead
PO43 phosphate
+
Table 2: Solubility of ions in water:
Ions that are soluble in water
Compounds with the following ions
are always soluble in water
Ammonium NH4+
Sodium Na+
Potassium K+
Nitrate NO3
Compounds with the following ions
are mostly soluble in water
Chloride Cl except with silver, Ag+, or lead, Pb2+
Sulfate SO42 except with silver, Ag+, or lead, Pb2+
Ions that are not soluble in water
Compounds with the following ions
are mostly not soluble in water
Hydroxide OH
Sulfide S2
Carbonate CO32
Phosphate PO43
except with
Ammonium NH4+
Sodium Na+
Potassium K+
Table 3: Molar mass of selected elements:
Element
Molar mass
(g per mol)
H
C
O
Ne
Na
Cl
Pb
1.0
12.0
16.0
20.1
23.0
35.5
207.2
Table 4: Molar mass of gases
STP standard temperature and pressure
temperature 0°C, pressure 101.3 kPa
One mol of any gas occupies
22.4 litres at STP
SLC standard laboratory conditions
temperature 25°C, pressure 101.3 kPa
One mol of any gas occupies
24.5 litres at SLC
Before you start
Page 2
CHEMISTRY
UNITS 3 and 4
PRETEST QUESTIONS
1.
Use the Periodic Table given on the previous page to help you answer the following
questions.
(a)
What is the atomic number of the following elements
(i)
silver
(ii)
radon
(iii)
radium
½ + ½ + ½ = 1½ marks
(b)
What is the chemical symbol of the following elements
(i)
gold
(ii)
silicon
(iii)
sodium
(iv)
antimony
½ + ½ + ½ + ½ = 2 marks
(c)
Identify the element with 13 protons and 13 neutrons.
1 mark
2.
Butane, C4H10 is commonly used in LPG and lighter fluid. It’s melting and boiling points
are shown below.
melting point/ freezing (solidification) point
boiling (evaporation) point/ condensation point
138 ºC
0.5 ºC
Circle the physical state of butane
at room temperature, 25 C
 solid
 liquid  gas
at fridge temperature, 4 C
 solid
 liquid  gas
at 5 C
 solid
 liquid  gas
½ + ½ + ½ = 1½ marks
Use the table of ions (Table 1) on the data page to help you answer questions 3 and 4.
3.
Identify the ions present in the following ionic compounds and name the compound.
(a)
MgCl2
(b)
Na3PO4
(c)
Ag2S
3 marks
4.
Work out the chemical formula of the following compounds.
(a) Silver hydroxide
(b) Magnesium carbonate
(c) Zinc nitrate
3 marks
5.
Balance the following chemical equations.
(a)
Mg(s) + N2(g)  Mg3N2(s)
(b)
Ca(S) + O2(g)  CaO(s)
(c)
H2(g) + O2(g)  H2O(l)
(d)
Al (s) + I2 (l)  Al2I6(s)
4 marks
Before you start
Page 3
Pre-test questions continued…
6.
Use the solubility table (Table 2) on the data page to determine which of the following
ionic compound are soluble.
(a)
lead sulfate
(b)
silver chloride
(c)
ammonium chloride
(d)
zinc carbonate
½ + ½ + ½ + ½ = 2 marks
7.
The compound Cu(NO3)2 dissolves in water by dissociation of ions
(a)
Identify the ions in the compound.
(b)
Write the ionic equation of the dissociation reaction. Show the state of each
compound or ion.
1 + 2 = 3 marks
Refer to the molar mass of elements (Table 3) on the data page to help you answer questions 8,
9 and 10.
8.
Find the molar mass of the following compounds
(a)
H2O
(b)
NaCl
2 marks
9.
Find the mass of 1.3 mol of CH4
1 mark
10.
Calculate the number of mol contained in the following samples, rounded to three decimal
places.
(a)
50 g of lead
(b)
62 g of NaCl
2 marks
Refer to the molar volume of gases (Table 4) on the data page to help you answer the following
question.
11. (a)
(b)
Work out the volume of 1.4 mol of chlorine (Cl2) at STP
Work out the mass of 2.8 L of neon (Ne) gas at SLC
1 + 1 = 2 marks
The table below summarises the different types of acid reactions:
Reactions of acids
1. acid + metal  salt + hydrogen
This reaction does not occur with Cu, Hg, or Ag.
2. acid + metal carbonate
 salt + water + carbon dioxide
3. acid + metal oxide  salt + water
4. acid + metal hydroxide  salt + water
Carbonates contain the CO32 ion
The chemical formulae of selected compounds.
HCl (aq)
Na2CO3 (aq)
NaCl (aq)
H2O (l)
CO2 (g)
CuO (s)
CuCl2 (aq)
H2O (l)
H2SO4 (aq)
NaOH (aq)
Na2SO4 (aq)
Before you start
Page 4
Pre-test questions continued…
12. Use the summary of acid reactions shown above to predict the products of the following
reactions:
(a) HCl (aq) + Mg (s) 
(b)
HCl (aq) + Na2CO3 (aq) 
(c)
HCl (aq) + CuO (s) 
(d)
H2SO4 (aq) + NaOH (aq) 
1 + 1 + 1 + 1 = 4 marks
13. Are the following reactions oxidation or reduction reactions?
(a)
Cl2(g) + 2e  2Cl (aq)
(b)
Pb (s)  Pb2+ (aq) + 2e
½ + ½ = 1 mark
14. The reaction Zn(s) + S(s)  ZnS (aq) can be written as two half reactions:
Zn(s)  Zn2+(aq) + 2e and S(s) + 2e  S2 (aq)
(a)
Identify the oxidant in this redox reaction
(d)
Identify the reductant in this redox reaction
½ + ½ = 1 mark
15.
Iron reacts with hydrochloric acid according to the ionic equation
Fe(s) + 2H+(aq)  Fe2+(aq) + H2(g)
(a)
What has been oxidised in this reaction?
(b)
Write a half equation for the oxidation reaction.
(d)
What has been reduced in this reaction?
(e)
Write a half equation for the reduction reaction.
½ + 1 + ½ + 1 = 3 marks
16.
Hydrogen gas and oxygen gas react to form water according to the reaction
2H2 (g) + O2 (g)  2H2O (l)
10 g of oxygen is reacted in excess hydrogen.
(a)
How many mol of oxygen was reacted?
(b)
How many mole of hydrogen is required?
(c)
Work out the mass of hydrogen reacted.
1 + 1 + 1 = 3 marks
END OF PRE-TEST
Before you start
Page 5
PRE TEST ANSWERS
1.
(a)
The atomic number of
(i)
(b)
silver 47
2.
3.
gold Au
(ii)
silicon Si
7.
(iii)
sodium Na
(iv)
antimony Sb
at room temperature, 25 C
 solid
 liquid

gas
at fridge temperature, 4 C
 solid
 liquid

gas
at 5 C
 solid

liquid  gas
Identify the ions present in the following ionic compounds and name the compound.
MgCl2
(b)
Na3PO4
(c)
Ag2S
Mg2+ Cl
Na+ PO43
Ag+ S2
Magnesium chloride
Sodium phosphate
Silver sulfide
Work out the chemical formula of the following compounds.
(b) Magnesium carbonate
AgOH
6.
radium 88
The element with 13 protons and 13 neutrons is Aluminium
(a) Silver hydroxide
5.
(iii)
Circle the physical state of butane
(a)
4.
radon 86
The chemical symbol of
(i)
(c)
(ii)
(c) Zinc nitrate
MgCO3
Zn(NO3)2
Balance the following chemical equations.
(a)
3Mg(s) + N2(g)  Mg3N2(s)
(b)
2Ca (s) + O2(g)  2CaO(s)
(c)
2H2(g) + O2(g) 2H2O(l)
(d)
2Al(s) + 3I2(l)  Al2I6(s)
Use the solubility table (Table 2) on the data page to determine which of the following
ionic compound are soluble.
(a)
lead sulfate is insoluble
(b)
silver chloride is insoluble
(c)
ammonium chloride is soluble
(d)
zinc carbonate is insoluble
The compound Cu(NO3)2 dissolves in water by dissociation of ions
(a)
The ions in the compound. Cu2+ NO3
(b)
The ionic equation of the dissociation reaction, showing the state of each compound
or ion.
H 2O
Cu(NO3)2 (s)  Cu2+ (aq) + 2NO3(aq)
Before you start
8.
(a)
Page 6
Mr(H2O) = 18.0 g/mol
(b)
Mr(NaCl) = 58.5 g/mol
Pre-test answers continued…
9.
The mass of 1.3 mol of CH4 = 1.3  16.0 = 20.8 grams
10.
The number of mol, to three decimal places
(a) 50 g of lead =
11. (a)
(b)
50
207.2
mol = 0.241 mol
(b) 62 g of NaCl =
62
58.5
mol = 1.059 mol
The volume of 1.4 mol of chlorine (Cl2) at STP = 1.4  22.4 L = 31.36 Litres
Work out the mass of 2.8 L of neon (Ne) gas at SLC =
2.8
24.5
 20.18 = 2.306 grams
12. Use the summary of acid reactions shown above to predict the products of the following
reactions:
(a) 2HCl (aq) + Mg (s)  MgCl2 (aq) + H2 (g)
(b)
2HCl (aq) + Na2CO3 (aq)  2NaCl (aq) + H2O(l) + CO2(g)
(c)
2HCl (aq) + CuO (s)  CuCl2 (aq) + H2O(l)
(d)
H2SO4 (aq) + 2NaOH (aq)  Na2SO4 (aq) + 2H2O(l)
13. Are the following reactions oxidation or reduction reactions?
(a)
Cl2(g) + 2e  2Cl (aq) Reduction reaction
(b)
Pb (s)  Pb2+ (aq) + 2e
14. (a)
15.
Oxidation reaction
The oxidant in this redox reaction is S(s)
(d)
The reductant in this redox reaction Zn(s)
(a)
Fe(s) been oxidised in this reaction?
(b)
The oxidation reaction is Fe(s)  Fe2+(aq) + 2e
(d)
H+(aq) has been reduced in this reaction?
(e)
The reduction reaction is 2H+(aq) + 2e  H2(g)
16. (a)
The mol of oxygen was reacted =
10 g
32.0
= 0.3125 mol
(b)
The mole of hydrogen required = 2  0.3125 = 0.625 mol
(c)
The mass of hydrogen reacted = 0.625  2.0 = 1.25 grams
Before you start
Page 7
Your pre-test result… What we recommend …
If your score was less than
20
40
If you got less than half the pre-test right you will most
likely need a lot of time and support to make a success of
Year 12 Chemistry. Past experience has shown that
students scoring less than 20 out of 40 are not able to
continue with this subject because they find it too
difficult. We strongly recommend that you contact the
Chemistry teachers to discuss your options.
If you scored between 20 and 30 you will most
likely need revision support throughout the year to
develop the skills expected. This means making
extra time available for your studies, and perhaps
finding a tutor to help you. We suggest that you
consider realistically whether you will be able to
make the extra study time available. Contact the
Chemistry teachers to discuss your options.
If your score was between
20
30
and
40
40
If you scored between 30 and 40 you should be able
to cope with most of the skills expected. However,
you will also need to make regular study time a part
of your weekly schedule. If you have any concerns,
contact the DECV, and speak to the Chemistry
teachers.