Essential Chemistry SPM Question Bank
Chapter 3: Chemical Formulae and Equations
Paper 11)The diagram below shows the set-up of apparatus used to
determine the empirical
formula of metal oxide Y.
What is metal oxide Y? A Magnesium oxide
C Lead(II) oxide
B Sodium oxide
D Aluminium oxide2) Metal X forms an oxide that has a formula of
X2O3. If the formula of chloride ion
is Cl-, then the formula of the chloride compound of X isA
XCl
C XCl2B XCl3
D X2Cl33) The formula of carbonate ion and sulphate ion is CO32-
and NO3- respectively. If the formula of carbonate salt is J2CO3,
then the formula of nitrate salt of J isA JNO3
C J(NO3)2B J2NO3
D J2(NO3)34) What is the number of molecules found in 0.5 mol of
carbon dioxide?[NA = 6.02 x 1023 mol-1]
A 1.81 x 1023
C 6.02 x 1023B 5.00 x 1023
D 3.01 x 1023
5) What is the mass of nitrogen with 3.01 x 1023 molecules of
nitrogen?
[Relative atomic mass: N = 14; NA = 6.02 x 1023 mol-1]
A 3.5 g
C 14 g
B 7 g
D 28 g
6)
The equation above represents the reaction during the extraction
of iron from iron oxide. What is the mass of iron that can be
extracted from 116 g of iron oxide?[Relative atomic mass: O = 16;
Fe = 56]
A 15 g
C 42 g
B 28 g
D 84 g
7)
CaCO3 CaO + CO2The equation above shows the heating action on
calcium carbonate. What is the mass of calcium carbonate needed to
produce 240 cm3 of carbon dioxide at room temperature?[Relative
atomic mass: C = 12; O = 16; Ca = 40; Molar volume = 24 dm3 at room
conditions]
A 0.68 g
C 6.8 g
B 1.0 g
D 8.0 g
8) The diagram below shows a syringe that contains X g of carbon
dioxide at room temperature.
What is the value of X?
[Relative atomic mass: C = 12; O = 16; Molar volume = 24 dm3 at
room conditions]
A 0.11 g
C 1.1 g
B 0.22 g
D 2.2 g
9) The relative molecular mass of chlorine is 71. This means
that 71 g of chlorine contains [NA = 6 x 1023 mol-1]
I 1 mol of chlorine molecules II 2 mol of chlorine atomsIII 1
mol of chlorine atomIV 6 x 1023 chlorine moleculesA I and II
only
C III and IV onlyB II and IV only
D I, II and IV only10) 4.80 g of element P combines with 3.20 g
of element Q. What is the empirical formula for the compound that
is produced? [P = 24; Q = 16]
A PQ
C PQ2B P2Q
D P2Q311) What is the empirical formula of the carbon dioxide
molecule? A CO
C C2O4 B CO2
D C2O12) How many ions are there in 0.5 mol of aluminium
oxide?
[NA = 6 x 1023 mol-1]
A 1.5 x 1023
C 1.5 x 1024
B 3.0 x 1023
D 6.0 x 1023
13) Which of the following is the compound formula of iron(III)
sulphate?
[NA = 6 x 1023 mol-1]
A FeSO4
C Fe(SO4)3
B Fe3SO4
D Fe2(SO4)314) An organic compound has an empirical formula of
C3H7. If the relative molecular mass of the compound is 86, what is
the molecular formula of the compound?
[Relative atomic mass: H = 1; C = 12; NA = 6 x 1023 mol-1]
A C2H6
C C5H12
B C3H8
D C6H1415) The element X in the diagram above forms a compound
with chlorine.
Which of the following is the formula of the compound?
A XCl
C XCl4
B X2Cl
D X2Cl3Paper 2
Structured question
ture
(a) What is meant by empirical formula?
__________________________________________________________________(b)
Calculate the
(i) mass of copper that reacts
_______________________________________________________________
(ii) mass of oxygen that is removed________
______________________________________________________ (c) What is
the empirical formula of copper
oxide?______________________________________________________________________________________________________________________________________________________________________________________________________
(d) Write the chemical equation for the reaction that occurs in
this
experiment.__________________________________________________________________(e)
State one safety measure that should be taken during the
experiment.
_____________________________________________________________________(f)
A metal X is placed above hydrogen in the reactivity series of
metals. Can the empirical formula of metal oxide X be determined
using the method in this experiment? Explain your answer.
__________________________________________________________________________________________________________________________________________Essay
question
(a) The following is information regarding a carbon
compound:
(i) What is meant by empirical formula?
(ii) Determine the empirical formula of this compound.
(iii) Determine the molecular formula of this compound.(b)
Hexene is a hydrocarbon compound with an empirical formula of CH2.
The relative molecular mass of this compound is 84. When the
compound is burned in excess oxygen, O2, it forms carbon dioxide,
CO2, and water, H2O. 480 cm3 of carbon dioxide is produced in this
reaction at room temperature.
[Relative atomic mass: H = 1; C = 12; Molar volume = 24 dm3 at
room condition;
NA = 6.02 x 1023 mol-1](i) Determine the molecular formula of
this hydrocarbon compound.(ii) Name the reactant and the product of
this heating reaction.
(iii) Form a balanced chemical equation to represent the
reaction that occurs.
(iv) Calculate the number of moles of carbon dioxide
produced.
(v) What is the number of molecules of carbon dioxide
produced?
(vi) Calculate the mass of the hydrocarbon compound that
reacted.Paper 3
A student carried out an experiment to determine the number of
molecules of the water of crystallisation in copper(II) sulphate
crystals by using the apparatus below.
The apparatus and its content are weighed by using the digital
balance before and after the experiment.
ProcedureElectronic scale
An empty boiling tube is weighed.
The boiling tube and the copper(II) sulphate crystals are
weighed together.
The boiling tube and the anhydrous copper(II) sulphate are
weighed together.
(a) Complete the table below by stating the observation made in
this experiment.
ObservationInference
(i)
(ii)
(b) Record the results of the experiment to two decimal
places.Mass of the empty test tube
= _____________ g
Mass of the test tube + copper(II) sulphate crystals =
_____________ g
Mass of the test tube + anhydrous copper(II) sulphate =
_____________ g
(c)(i) Calculate the mass of anhydrous copper(II) sulphate.(ii)
Calculate the mass of the water of crystallisation.(d) Determine
the number of moles of the water of crystallisation that combines
with 1 mol of copper(II) sulphate.
[Relative atomic mass: H = 1; O = 16; S = 32; Cu = 64]
Fe3O4 3Fe + 2O2
The diagram above shows the set-up of apparatus that is used to
determine the empirical formula of copper oxide. The following
results are obtained:
Mass of combustion tube + empty asbestos dish = 31.78 g
Mass of combustion tube + empty asbestos dish + copper oxide =
33.58 g
Mass of combustion tube + asbestos dish + copper = 33.38 g
[Relative atomic mass: O = 16; Cu = 64]
Mass of carbon: 26.67g
Mass of oxygen: 71.11g
Mass of hydrogen: 2.22g
Relative molecular mass = 90
Relative atomic mass of H = 1, C = 12 and O = 16
