School
NGR
Welcome to Schoolngr.com
Home
School
News
C B T
Classroom
Exams
Search SchoolNGR
Search
Thursday, 18 June 2026
Register
.
Login
Your browser does not seems to have Javascript enabled. Please enable Javascript in order to use all the features of this website!
Chemistry Past Questions and Answers
Topic: Separation of mixtures and purification of chemical substances
Classroom
Jamb
Exam year:
Exam year
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
Question type:
Question type
Objective
Theory
Topics:
Topics
[1] Separation of mixtures and purification of chemical substances
[1].1 Pure and impure substances
[1].2 Boiling and melting points
[1].3 Elements, compounds and mixtures
[1].4 Chemical and physical changes
[1].5 Separation processes
[1].5.1 Evaporation
[1].5.2 Simple and fractional distillation
[1].5.3 Sublimation
[1].5.4 Filtration
[1].5.5 Crystallization
[1].5.6 Paper and column chromatography
[1].5.7 Simple and fractional crystallization
[1].5.8 Magnetization
[1].5.9 Decantation
[2] Chemical combination
[2].1 Laws of definite, multiple and reciprocal proportions
[2].2 Law of conservation of matter
[2].3 Gay Lussac's law of combining volumes
[2].4 Avogadro's law
[2].4.1 Chemical symbols
[2].4.2 Formulae
[2].4.3 Avogadro's law - equations and their uses
[2].4.4 Relative atomic mass based on C=12
[2].4.5 The mole concept and Avogadro's number
[2].4.6 Stoichiometry of reactions
[3] Kinetic theory of matter and Gas Laws
[3].1 Phenomena to support the kinetic theory of matter using
[3].1.1 Melting
[3].1.2 Vapourization
[3].1.3 Boiling
[3].1.4 Freezing
[3].1.5 Condensation in terms of molecular motion and Brownian movement
[3].2 The laws of Boyle
[3].3 The laws of Charles
[3].4 Graham and Dalton (law of partial pressure)
[3].5 Combined gas law
[3].6 Molar volume and atomicity of gases
[3].7 The ideal gas equation
[3].8 The relationship between vapour density of gases and the relative molecular mass
[4] Atomic structure and bonding
[4].1 The concept of atoms, molecules and ions
[4].2 The works of:
[4].2.1 Dalton
[4].2.2 Millikan
[4].2.3 Rutherford
[4].2.4 Moseley
[4].2.5 Thompson
[4].2.6 Bohr
[4].3 Atomic structure
[4].4 Electron configuration
[4].5 Atomic number
[4].6 Mass number
[4].7 Isotopes
[4].8 Shapes of s and p orbitals
[4].9 The periodic table and periodicity of elements
[4].9.1 Presentation of the periodic table with a view to recognizing families of elements - alkali metals
[4].9.2 Presentation of the periodic table with a view to recognizing families of elements - halogens
[4].9.3 Presentation of the periodic table with a view to recognizing families of elements - the noble gases
[4].9.4 Presentation of the periodic table with a view to recognizing families of elements - transition metals
[4].9.5 The variation of ionization energy
[4].9.6 The variation of ionic radii
[4].9.7 The variation of electron affinity
[4].9.8 The variation of electronegativity
[4].10 Chemical bonding
[4].10.1 Electrovalency and covalency
[4].10.2 The electron configuration of elements and their tendency to attain the noble gas structure
[4].10.3 Hydrogen bonding and metallic bonding as special types of electrovalency and covalency
[4].10.4 Coordinate bond as a type of covalent bond
[4].10.5 Van der Waals' forces should be mentioned as a special type of bonding forces
[4].11 Shapes of simple molecules
[4].11.1 Linear ((H, O, Cl,HCl and CO)
[4].11.2 Non-linear (HO) and tetrahedral
[4].11.3 (CH) and pyramidal (NH)
[4].12 Nuclear Chemistry
[4].12.1 Radioactivity
[4].12.1.1 Types and properties of radiations
[4].12.2 Nuclear reactions
[4].12.2.1 Simple equations
[4].12.2.2 uses and applications of natural and artificial radioactivity.
[5] Air
[5].1 The natural gaseous constituents and their proportion in the air
[5].1.1 Nitrogen
[5].1.2 Oxygen
[5].1.3 Water vapour
[5].1.4 Carbon (IV) oxide
[5].1.5 The noble gases (argon and neon)
[5].2 Air as a mixture and some uses of the noble gas
[6] Water
[6].1 Water as a product of the combustion of hydrogen and its composition by volume.
[6].2 Water as a solvent
[6].2.1 Atmospheric gases dissolved in water and their biological significance.
[6].3 Hard and soft water
[6].3.1 Temporary and permanent hardness and methods of softening hard water
[6].4 Treatment of water for town supply
[6].5 Water of crystallization
[6].5.1 Efflorescence
[6].5.2 Deliquescence and hygroscopy
[6].5.3 Examples of the substances exhibiting these properties and their uses.
[7] Solubility
[7].1 Unsaturated, saturated and supersaturated solutions
[7].1.1 Solubility curves and simple deductions from them
[7].1.2 Solubility defined in terms of mole per dm
[7].1.3 Simple calculations
[7].2 Solvents for fats, oil and paints
[7].2.1 The use of such solvents for the removal of stains
[7].3 True and False solution (Suspensions and colloids)
[7].3.1 Properties and examples
[7].3.2 Harmattan haze and water paints as examples of suspensions and fog
[7].3.3 Milk
[7].3.4 Aerosol spray
[7].3.5 Emulsion paints
[7].3.6 Rubber solution as examples of colloids
[8] Environmental Pollution
[8].1 Sources and effects of pollutants
[8].2 Air pollution
[8].2.1 Examples of air pollutants such as H₂S, CO, SO₂, oxides of nitrogen, chlorofluorocarbons and dust
[8].3 Water pollution
[8].3.1 Sewage and oil pollution should be known
[8].4 Soil pollution
[8].4.1 Oil spillage
[8].4.2 Biodegradable pollutants
[8].4.3 Non-biodegradable pollutants
[9] Acids, bases and salts
[9].1 General characteristics and properties of acids
[9].2 General characteristics and properties of Bases and salts
[9].3 Acids/base indicators
[9].4 Basicity of acids
[9].5 Normal, acidic, basic and double salts
[9].6 An acid defined as a substance whose aqueous solution furnishes H3O+ ions or as a proton donor
[9].7 Ethanoic, Citric and tartaric acids as examples of naturally occurring organic acids
[9].8 Alums as examples of double salts
[9].9 Preparation of salts by neutralization
[9].10 Precipitation and action of acids on metals
[9].11 Oxides and trioxocarbonate (IV) salts
[9].12 Qualitative comparison of the conductances of molar solutions of strong and weak acids and bases
[9].13 Relationship between conductance and amount of ions present
[9].14 pH and pOH scale
[9].14.1 Simple calculations
[9].15 Acid/base titrations
[9].16 Hydrolysis of salts
[9].16.1 Simple of Hydrolysis Of Salts examples such as NH₄Cl, AlCl₃, Na₂CO₃, CH₃COONa
[10] Oxidation and Reduction - Redox
[10].1 Oxidation in terms of the addition of oxygen or removal of hydrogen
[10].2 Reduction as removal of oxygen or addition of hydrogen
[10].3 Oxidation and reduction in terms of electron transfer
[10].4 Use of oxidation numbers
[10].5 IUPAC nomenclature of inorganic compounds using oxidation number
[10].6 Tests for oxidizing and reducing agents
[11] Electrolysis
[11].1 Electrolytes and non-electrolytes
[11].1.1 Faraday's laws of electrolysis
[11].2 Electrolysis of dilute H₂SO₄
[11].3 Aqueous CuSO₄
[11].4 CuCl₂ solution
[11].5 Dilute and concentrated NaCl solutions
[11].6 Fused NaCl
[11].7 Factors affecting discharge of ions at the electrodes
[11].8 Uses of electrolysis
[11].8.1 Purification of metals
[11].9 Electrochemical cells
[11].9.1 Electrochemical series (K, Ca,Na, Mg, Al, Zn, Fe, Sn, Pb, H, Cu, Hg, Ag, Au,)
[11].9.2 half-cell reactions and electrode potentials.
[11].10 Corrosion as an electrolytic process
[11].10.1 Cathodic protection of metals
[11].10.2 Painting as ways of preventing iron from corrosion.
[11].10.3 Electroplating and coating with grease as ways of preventing iron from corrosion.
[12] Energy changes
[12].1 Energy changes ∆H accompanying physical and chemical changes
[12].1.1 Dissolution of substances in/or reaction with water
[12].2 Entropy as an order-disorder phenomenon
[12].2.1 Simple illustrations like mixing of gases and dissolution of salts.
[12].3 Spontaneity of reactions
[12].3.1 ΔG° = 0 as a criterion for equilibrium
[12].3.2 ∆G greater or less than zero as a criterion for non-spontaneity or spontaneity
[13] Rates of Chemical Reaction
[13].1 Elementary treatment of the following factors which can change the rate of a chemical reaction
[13].1.1 Temperature
[13].1.2 Concentration/Pressure
[13].1.3 Surface area
[13].1.4 Catalyst
[13].2 Reaction rate curves
[13].3 Activation energy
[13].3.1 Qualitative treatment of Arrhenius' law and the collision theory
[13].3.2 Effect of light on some reactions
[14] Chemical equilibra
[14].1 Reversible reactions and factors governing the equilibrium position
[14].2 Dynamic equilibrium
[14].3 Le Chatelier's principle and equilibrium constant
[15] Non-metals and their compounds
[15].1 Hydrogen
[15].1.1 Commercial production from water gas and cracking of petroleum fractions
[15].1.2 Laboratory preparation
[15].1.3 Properties, uses and test for hydrogen
[15].2 Halogens
[15].2.1 Chlorine as a representative element of the halogen
[15].2.2 Laboratory preparation
[15].2.3 Industrial preparation by electrolysis, properties and uses
[15].2.4 Hydrogen chloride and Hydrochloric acid
[15].2.5 Chlorides and test for chlorides
[15].3 Oxygen and Sulphur
[15].3.1 Oxygen
[15].3.1.1 Laboratory preparation, properties and uses
[15].3.1.2 Commercial production from liquid air
[15].3.1.3 Oxides: Acidic, basic, amphoteric and neutral
[15].3.1.4 Trioxygen (ozone) as an allotrope and the importance of ozone in the atmosphere
[15].3.2 Sulphur
[15].3.2.1 Uses and allotropes
[15].3.2.2 Preparation, properties and uses of sulphur (IV) oxide
[15].3.2.3 the reaction of SO2 with alkalis.
[15].3.2.4 Trioxosulphate (IV) acid and its salts
[15].3.2.5 Tetraoxosulphate(VI) acid
[15].3.2.5.1 Commercial preparation (contact process only)
[15].3.2.5.2 properties as a dilute acid
[15].3.2.5.3 An oxidizing and a dehydrating agent and uses
[15].3.2.5.4 Test for SO₄²⁻
[15].3.2.6 Hydrogen sulphide
[15].3.2.6.1 Preparation and properties as a weak acid
[15].3.2.6.2 reducing and precipitating agents
[15].3.2.6.3 Test for S²⁻
[15].4 Nitrogen
[15].4.1 Laboratory preparation
[15].4.2 Production from liquid air
[15].4.3 Ammonia
[15].4.3.1 Laboratory and industrial preparations (Haber Process only)
[15].4.3.2 properties and uses
[15].4.3.3 ammonium salts and their uses
[15].4.3.4 oxidation of ammonia to nitrogen (IV) oxide and trioxonitrate (V) acid
[15].4.3.5 Test for NH₄⁺
[15].4.4 Trioxonitrate (V) acid
[15].4.4.1 Laboratory preparation from ammonia
[15].4.4.2 properties and uses..
[15].4.4.3 Trioxonitrate (V) salt - action of heat and uses.
[15].4.4.4 Test for NO₃⁻
[15].4.5 Oxides of nitrogen
[15].4.5.1 Properties.
[15].4.5.2 The nitrogen cycle
[15].5 Carbon
[15].5.1 Allotropes - Uses and properties
[15].5.2 Carbon(IV) oxide
[15].5.2.1 Laboratory preparation, properties and uses,,
[15].5.2.2 Action of heat on trioxocarbonate (IV) salts and test for CO₃²⁻
[15].5.3 Carbon(II) oxide
[15].5.3.1 Laboratory preparation, properties including its effect on blood
[15].5.3.2 sources of carbon (II) oxide to include charcoal, fire and exhaust fumes.
[15].5.4 Coal
[15].5.4.1 Different types
[15].5.4.2 products obtained from destructive distillation of wood and coal.
[15].5.5 Coke
[15].5.5.1 Gasification and uses.
[15].5.5.2 Manufacture of synthesis gas and uses.
[16] Metals and their compounds
[16].1 General properties of metals
[16].2 Alkali metals
[16].2.1 Sodium hydroxide
[16].2.2 Sodium trioxocarbonate (IV) and sodium hydrogen trioxocarbonate (IV)
[16].2.3 Sodium chloride
[16].3 Alkaline-earth metals
[16].3.1 Properties and uses of Alkaline-earth
[16].3.2 Preparation of calcium oxide from sea shells
[16].3.3 The chemical composition of cement and the setting of mortar
[16].4 Aluminium
[16].4.1 Purification of bauxite
[16].4.2 Electrolytic extraction
[16].4.3 Properties and uses of aluminium and its compounds
[16].5 Tin
[16].5.1 Extraction from its ores
[16].5.2 Properties and uses
[16].6 Metals of the first transition series, Characteristic properties
[16].6.1 Electron configuration
[16].6.2 Oxidation states
[16].6.3 Complex ion formation
[16].6.4 Formation of coloured ions
[16].6.5 Catalysis
[16].7 Iron
[16].7.1 Extraction from sulphide and oxide ores
[16].7.2 Properties and uses of Iron
[16].7.3 Different forms of iron and their properties and advantages of steel over iron
[16].8 Copper
[16].8.1 Extraction from sulphide and oxide ores.
[16].8.2 Properties and uses of copper
[16].8.3 Preparation and uses of copper(II) tetraoxosulphate(VI)
[16].8.4 Test for Cu²⁺
[16].9 Alloy
[16].9.1 Steel, stainless steel, brass, bronze (constituents and uses only).
[16].9.2 type-metal, duralumin, soft solder, permallory and alnico (constituents and uses only).
[17] Organic Compounds
[17].1 Aliphatic hydrocarbons
[17].1.1 Alkanes
[17].1.1.1 Homologous series in relation to physical properties
[17].1.1.2 Substitution reaction and a few examples and uses of halogenated products
[17].1.1.3 Isomerism - structural only
[17].1.1.4 Petroleum - composition, fractional distillation and major products
[17].1.1.5 Petrochemicals - starting materials of organic syntheses, quality of petrol and meaning of octane number
[17].1.2 Alkenes
[17].1.2.1 Isomerism: structural and geometric isomerism
[17].1.2.2 additional and polymerization reactions
[17].1.2.3 polythene and synthetic rubber as examples of products of polymerization and its use in vulcanization.
[17].1.3 Alkynes
[17].1.3.1 Ethyne – production from action of water on carbides, simple reactions and properties of ethyne.
[17].2 Aromatic hydrocarbons
[17].2.1 Benzene - structure, properties and uses
[17].3 Alkanols
[17].3.1 Primary, secondary, tertiary - production of ethanol by fermentation and from petroleum by-products
[17].3.2 Local examples of fermentation and distillation
[17].3.3 Reactions of OH group
[17].4 Alkanals and alkanones
[17].4.1 Chemical test to distinguish between alkanals and alkanones
[17].5 Alkanoic acids
[17].5.1 Chemical reactions
[17].5.2 Neutralization and esterification
[17].5.3 Ethanedioic (oxalic) acid as an example of a dicarboxylic acid and benzene carboxylic acid as an example of an aromatic acid.
[17].6 Alkanoates
[17].6.1 Formation from alkanoic acids and alkanols
[17].6.2 Saponification
[17].6.2.1 Production of soap and margarine from alkanoates and distinction between detergents and soaps.
[17].7 Amines (Alkanamines) Primary, Secondary, and tertiary
[17].8 Carbohydrates
[17].8.1 Classification – mono-, di- and polysaccharides; composition, chemical tests for simple sugars and reaction with concentrated tetraoxosulphate (VI) acid
[17].8.2 Hydrolysis of complex sugars
[17].8.3 the uses of sugar and starch in the production of alcoholic beverages, pharmaceuticals and textiles.
[17].9 Proteins
[17].9.1 Primary structures, hydrolysis and tests (Ninhydrin, Biuret, Millon’s and xanthoproteic)
[17].9.2 Enzymes and their functions
[17].10 Polymers
[17].10.1 Natural and synthetic rubber
[17].10.2 Addition and condensation polymerization
[17].10.3 Methods of preparation, examples and uses.
[17].10.4 Thermoplastic and thermosetting plastics
[18] Chemistry and Industry
[18].1 Chemical industries
[18].1.1 Types of Chemical industries
[18].1.2 Raw materials of Chemical industries
[18].1.3 Relevancies of Chemical industries
[18].1.4 Biotechnology
Jamb Chemistry Questions - Separation of mixtures and purification of chemical substances
Question 261:
JAMB 2007
How long would it take to deposit 0.08g of copper from CuCl
2
solution by passing a current of 0.5A?
[Cu = 64, F = 96500 C mol
-1
]
SchoolNGR Classroom
A
6 mins
B
8 mins
C
24 mins
D
48 mins
View Answer & Explanation
Question 262:
JAMB 2007
MnO
2(s)
+ xHCl
(aq)
→ MnCl
2(aq)
+ yH
2
O
(l)
+ zCl
2(g)
In theequation above, what are the values of x, y and z respectively
SchoolNGR Classroom
A
2, 1, 2
B
4, 1, 2
C
4, 2, 1
D
1, 2, 1
View Answer & Explanation
Question 263:
JAMB 2007
A mixture of petrol and water can be separated through
SchoolNGR Classroom
A
Centrifugation
B
Distillation
C
The use of separating funnel
D
The use of filter paper
View Answer & Explanation
Question 264:
JAMB 2007
How many structural isomers of chlorobutane are possible?
SchoolNGR Classroom
A
4
B
3
C
2
D
1
View Answer & Explanation
Question 265:
JAMB 2007
Certain useful waxes are composed mainly of
SchoolNGR Classroom
A
Amino acids
B
Glycerols
C
Alkanols
D
Alkanoates
View Answer & Explanation
First
← Prev
52
53
Next →
Stay Updated
Follow us on:
Facebook
X
Subjects
Accounts - Principles of Accounts
Animal Husbandry
Aptitude Test
Agricultural Science
Arabic
Auto Mechanics
Basic Electronics
Biology
Bookkeeping
Block laying, bricklaying, and concreting work
Chemistry
Clothing and Textiles
Carpentry and joinery
Commerce
Christian Religious Studies (CRS)
Civic Education
Catering craft practice
Computer Studies
Current Affairs
Data Processing
Load More Subject