CRACKIT_TERM 2 EXAMS
International General Certificate of Secondary Education
CHEMISTRY
PAPER 4-Extended
FORM 4
STUDENT NAME
Time = 1 hour 45 minutes
Read me before writing
Answer all questions
Use a blue and black pen when writing your answers.
The use of a calculator is allowed.
Marks = 80
Question 1
Complete the table below to show the number of sub-atomic particles in both an atom
and an ion of potassium.
[6]
Question 2
Draw a ‘dot and cross’ diagram for carbon dioxide. Show the outer shell electrons
only. [5]
Question 3
(a) Balance the equation for the combustion of butane.[2]
2C4H10 + O2 → CO2 + H2O
(b) Sodium hydride, NaH, reacts with iron(III) oxide.
Balance the equation for this reaction [2]
(c) Complete the chemical equation for the reaction of potassium with water to
form potassium hydroxide and hydrogen gas [2] and balance
(d) Balance the chemical equation for the reaction of hydrogen sulfide with sulfur
dioxide shown. [3]
Question 4
Substances can be classified as elements, compounds or mixtures.
(a) What is meant by the term compound?
..........................................................................................................................................
..........................................................................................................................................
...................................................................................................................................[2]
Question 5
Flerovium, Fl, atomic number 114, was first made in research laboratories in 1998.
(a) In which period of the Periodic Table is flerovium?
.........................................................................................................[1]
(b) Predict the number of outer shell electrons in an atom of flerovium.
..........................................................................................................[1]
(c) Two isotopes of flerovium are 286 Fl and 289 Fl.
The nuclei of both of these isotopes are unstable and emit energy when they split up.
(i) State the term used to describe isotopes with unstable nuclei
--------------------------------------------[1]
Question 6
(a) Give the formulae of the ions in ammonium sulfate.
.................................................... and ........................................... [1]
Question 7
Element X can undergo the following physical changes
(a) Give the scientific name for each of the numbered
physical changes. [4]
1………………………………
2………………………………
3………………………………
4……………………………..
Question 8
The diagrams show part of the structures of five substances, A, B, C, D and E
Answer the following questions about these structures. Each structure may be used
once, more than once or not at all.
(a) Which two of these structures, A, B, C, D or E, are covalently bonded?
..........................................................and..........................................[2]
(b) Which one of these structures, A, B, C, D or E, is a diatomic molecule?
........................................................................................................................[1]
(c) Which one of these structures, A, B, C, D or E, is a compound?
..................................................................................................................... [1]
(d) Which one of these structures, A, B, C, D or E, is very soluble in water?
...................................................................................................................... [1]
(e) Which one of these structures, A, B, C, D or E, is used in cutting tools?
....................................................................................................................... [1]
Question 9
(a) Complete the table to show the relative charge and approximate relative mass
of a proton, a neutron and an electron. [4]
(b) Deduce the number of electrons and neutrons in an atom of the isotope of iron
58
shown. Fe26
number of electrons
.................................................................................................................[1]
number of neutrons
...................................................................................................................[1]
(c) Caesium is a radioactive element with a proton number of 55.
(i) Define the term proton number.
…………………………………………………………………………..[1]
Question 10
(a) The names and formulae for some compounds are shown.
Deduce the formula for magnesium phosphate.
........................................................................................................................... [2]
(b) Name the compound that contains NH4+ and Cl– ions.
.................................................................................................................[1]
(c) Name the compound that contains Mg2+ and SO42– ions.
...........................................................................................................................[1]
Question 11
The electronic structures of five atoms, A, B, C, D and E, are shown.
Answer the following questions about these electronic structures.
Each electronic structure may be used once, more than once or not at all. State which
electronic structure, A, B, C, D or E, represents:
(a) an atom in Group II of the Periodic Table
.........................................................................................................................[1]
(b) an atom with a proton number of 13
.........................................................................................................................[1]
(c) an atom that forms a ion with a single negative charge
.........................................................................................................................[1]
(d) an atom of a non-metal that forms a giant covalent structure
........................................................................................................................ [1]
Question 13
(a) Explain why magnesium ions have a charge of 2+.
...................................................................................................................
...................................................................................................................[2]
(b) Give the electronic structure for Mg2+ ions.
….. , …… [1]
Question 14
Some properties of sodium chloride are shown:
● melting point of 801 °C
● non-conductor of electricity when solid
● conductor of electricity when molten
● soluble in water.
(a) Name the type of bonding in sodium chloride.
.................................................................................................................[1]
(c) In the space below drawing the dot and cross diagram of the bonding in
Sodium Chloride and the resulting charges. [6]
Question 15
(a) Element X is a Group 1 metal. It burns in air to form an oxide X2O. Write a
chemical equation for this reaction. [5]
Question 17
(a) Ester Y has the following composition by mass:
Carbon 48.65%; Hydrogen 8.11%; Oxygen 43.24%.
Calculate the empirical formula of ester Y [6]
(b) Ester Z has the empirical formula C2H4O and a relative molecular mass of 88.
Determine the molecular formula of ester Z [3]
Question 18
(a) Calculate the relative molecular mass of this compound C6H4Cl2 .
……………………………..[2]
(b) If this compound C6H4Cl2 has a mass of 48g calculate its moles
……………[2]
(c) This compound C6H4Cl2 decomposes to produce 3 moles of chlorine gas.
Calculate the volume occupied by the chlorine gas produced at room temperature and
pressure.
……………………..[2]
The END
