2020 paper
Particulate Nature of Matter
Evidence of Particulate Nature:
The following processes provide evidence of the particulate nature of matter:
I. Diffusion
II. Filtration
III. Osmosis
The correct combinations for the evidence of the particulate nature are:
(A) I and II only
(B) I and III only
(C) II and III only
(D) I, II and III
Chemistry Concepts
Mass Number:
Definition: The mass number is the number of
(A) neutrons plus protons
(B) neutrons minus protons
(C) electrons plus neutrons
(D) electrons plus protons
Identifying Anions:
The following elements are discussed:
Element Q, R, S, and T
Among them, to determine which element is an anion:
(A) Q
(B) R
(C) S
Isotopes
Isotope Identification:
The arrangement of electrons in elements X and Y:
X: 2, 8, 5
Y: 2, 8, 6
The isotopes represented are:
(A) Q and R
(B) R and T
(C) Q and S
(D) S and T
Acid Formation
Acid Formation:
Which acids will NOT form an acid salt?
(A) H₃PO₄
(B) H₂CO₃
(C) H₂SO₄
(D) CH₃COOH
Ion Conversion
Ion Conversion to Neutral Atom:
An ion with a single negative charge may become neutral by:
(A) losing a neutron
(B) gaining a proton
(C) losing an electron
(D) gaining an electron
Aqueous Solutions
Hydrogen Ions in Aqueous Solutions:
Which aqueous solution contains 1 mole of hydrogen ions?
(A) 2 dm³ of 0.5 mol/dm³ HCl
(B) 2 dm³ of 0.5 mol/dm³ H₂SO₄
(C) 1 dm³ of 1.0 mol/dm³ H₂SO₄
(D) 1 dm³ of 1.0 mol/dm³ CH₃COOH
Separation Techniques
Mixture Separation:
A separating funnel can be used to separate mixtures like:
(A) water and ethanol
(B) water and kerosene
(C) water and solid sodium chloride
(D) kerosene and solid sodium chloride
Chemical Compounds
Correct Formula of Compounds:
When a new element, R, shows chemical properties similar to sodium, the correct formula for a compound formed with sulfur is:
(A) RS₂
(B) RS
(C) R₂S
(D) R₂S₂
Bonding Types
Metallic Bond Formation:
The formation of a metallic bond is best described as:
(A) Anions are held together by electrons.
(B) Metal atoms are held together by anions.
(C) Metal ions are held together by a sea of anions.
(D) Cations are held together by a sea of mobile electrons.
Covalent Compounds
Formation of Covalent Compounds:
Covalent compounds can be formed:
(A) between a metal and a non-metal
(B) between a positive ion and a negative ion
(C) between two identical non-metal atoms, excluding noble gases
(D) between two identical non-metal atoms, including noble gases
Graphite Properties
Graphite as Lubricant:
Graphite can be used as a lubricant because of:
(A) loose electrons which can move throughout the lattice
(B) weak attraction among the hexagonal layers of carbon atoms
(C) strong attraction among the hexagonal layers of carbon atoms
(D) strong attraction within the hexagonal layers of carbon atoms
Reactions and Compounds
Common Reactions:
The reaction discussed:
ext{NO}_2(g) + ext{O}_2(g)
ightarrow ext{NO}(g) + ext{SO}_2(g)Identifying reduced and oxidizing agents in reactions:
Compounds involved:
(A) NO
(B) NO₂
(C) SO₂
(D) SO₃
Acids and Bases
Properties of Acids:
Which of the following acids is weakly ionized in aqueous solutions?
(A) Nitric acid
(B) Ethanoic acid
(C) Sulfuric acid
(D) Hydrochloric acid
Identification Tests
Tests for Gases:
Tests for identifying ammonia gas and acidic gases.
Test question:
(A) Damp blue litmus paper changes to red
(B) Glowing splint relights
(C) Damp red litmus paper changes to blue
(D) Lit splint extinguishes with a pop
Electricity and Chemistry
Electrical Conductivity:
Which of the following will NOT conduct electricity?
(A) Solid calcium
(B) Solid calcium chloride
(C) Molten calcium chloride
(D) A solution of calcium chloride in water
Elemental Chemistry
Boiling Point Graph:
Discussing boiling points and properties of alcohols with respect to the number of carbon atoms.
Relevant equation:
Graph shows boiling points (°C) against the number of carbon atoms in a chain.
Hydrocarbons
Cracking and Producing Salaried Hydrocarbons:
Products obtained by cracking the alkane, CH₃:
(A) C₂H₆
(B) C₃H₈
(C) C₂H₄
Reaction Types
Esterification and Reactions:
Reaction equation: Organic Acid + Alcohol → Ester + Water.
Forward reaction characterized as:
(A) Synthesis
(B) Hydrolysis
(C) Esterification
(D) Polymerization
Homologous Series
Features of Homologous Series:
Which of the following features is NOT true for all homologous series of compounds?
(A) the same functional group
(B) the same general formula
(C) similar chemical properties
(D) the same empirical formula
Isomer Count
Isomers of Butane:
How many isomers of butane, C₄H₁₀, are there?
Options:
(A) 1
(B) 2
(C) 3
(D) 4
Laboratory Techniques
Preparation of Ammonia Gas:
A suitable drying agent for the laboratory preparation of ammonia gas:
(A) calcium oxide
(B) calcium chloride
(C) anhydrous copper sulfate
(D) concentrated sulfuric acid
Preparing Compounds
Observations in Compound Reactions:
Observations when aqueous silver nitrate is added to aqueous potassium chloride:
(A) A pungent gas is evolved.
(B) A blue precipitate appears.
(C) A white precipitate appears.
(D) A brown precipitate appears.
Organic Reactions
Hydrocarbon Reactions:
Discussing reactions and products formed from hydrocarbons:
Key compounds mentioned: Ethanol, propene, and vinegar.
Conclusion of Test
The test concludes with instructions for reviewing answers.
Graphs and additional details provided for clarity in chemical properties and reactions.
Particulate Nature of Matter
Evidence of Particulate Nature:
The following processes provide evidence of the particulate nature of matter:
I. Diffusion
II. Filtration
III. Osmosis
The correct combinations for the evidence of the particulate nature are:
(A) I and II only
(B) I and III only
(C) II and III only
(D) I, II and III
Chemistry Concepts
Mass Number:
Definition: The mass number is the number of
(A) neutrons plus protons
(B) neutrons minus protons
(C) electrons plus neutrons
(D) electrons plus protons
Identifying Anions:
The following elements are discussed:
Element Q, R, S, and T
Among them, to determine which element is an anion:
(A) Q
(B) R
(C) S
Isotopes
Isotope Identification:
The arrangement of electrons in elements X and Y:
X: 2, 8, 5
Y: 2, 8, 6
The isotopes represented are:
(A) Q and R
(B) R and T
(C) Q and S
(D) S and T
Acid Formation
Acid Formation:
Which acids will NOT form an acid salt?
(A) H₃PO₄
(B) H₂CO₃
(C) H₂SO₄
(D) CH₃COOH
Ion Conversion
Ion Conversion to Neutral Atom:
An ion with a single negative charge may become neutral by:
(A) losing a neutron
(B) gaining a proton
(C) losing an electron
(D) gaining an electron
Aqueous Solutions
Hydrogen Ions in Aqueous Solutions:
Which aqueous solution contains 1 mole of hydrogen ions?
(A) 2 dm³ of 0.5 mol/dm³ HCl
(B) 2 dm³ of 0.5 mol/dm³ H₂SO₄
(C) 1 dm³ of 1.0 mol/dm³ H₂SO₄
(D) 1 dm³ of 1.0 mol/dm³ CH₃COOH
Separation Techniques
Mixture Separation:
A separating funnel can be used to separate mixtures like:
(A) water and ethanol
(B) water and kerosene
(C) water and solid sodium chloride
(D) kerosene and solid sodium chloride
Chemical Compounds
Correct Formula of Compounds:
When a new element, R, shows chemical properties similar to sodium, the correct formula for a compound formed with sulfur is:
(A) RS₂
(B) RS
(C) R₂S
(D) R₂S₂
Bonding Types
Metallic Bond Formation:
The formation of a metallic bond is best described as:
(A) Anions are held together by electrons.
(B) Metal atoms are held together by anions.
(C) Metal ions are held together by a sea of anions.
(D) Cations are held together by a sea of mobile electrons.
Covalent Compounds
Formation of Covalent Compounds:
Covalent compounds can be formed:
(A) between a metal and a non-metal
(B) between a positive ion and a negative ion
(C) between two identical non-metal atoms, excluding noble gases
(D) between two identical non-metal atoms, including noble gases
Graphite Properties
Graphite as Lubricant:
Graphite can be used as a lubricant because of:
(A) loose electrons which can move throughout the lattice
(B) weak attraction among the hexagonal layers of carbon atoms
(C) strong attraction among the hexagonal layers of carbon atoms
(D) strong attraction within the hexagonal layers of carbon atoms
Reactions and Compounds
Common Reactions:
The reaction discussed:
NO2(g) + O2(g) \rightarrow NO(g) + SO_2(g)Identifying reduced and oxidizing agents in reactions:
Compounds involved:
(A) NO
(B) NO₂
(C) SO₂
(D) SO₃
Acids and Bases
Properties of Acids:
Which of the following acids is weakly ionized in aqueous solutions?
(A) Nitric acid
(B) Ethanoic acid
(C) Sulfuric acid
(D) Hydrochloric acid
Identification Tests
Tests for Gases:
Tests for identifying ammonia gas and acidic gases:
(A) Damp blue litmus paper changes to red
(B) Glowing splint relights
(C) Damp red litmus paper changes to blue
(D) Lit splint extinguishes with a pop
Electricity and Chemistry
Electrical Conductivity:
Which of the following will NOT conduct electricity?
(A) Solid calcium
(B) Solid calcium chloride
(C) Molten calcium chloride
(D) A solution of calcium chloride in water
Elemental Chemistry
Boiling Point Graph:
Discussing boiling points and properties of alcohols with respect to the number of carbon atoms.
Relevant equation:
Graph shows boiling points (°C) against the number of carbon atoms in a chain.
Hydrocarbons
Cracking and Producing Salaried Hydrocarbons:
Products obtained by cracking the alkane, CH₃:
(A) C₂H₆
(B) C₃H₈
(C) C₂H₄
Reaction Types
Esterification and Reactions:
Reaction equation: Organic Acid + Alcohol → Ester + Water.
Forward reaction characterized as:
(A) Synthesis
(B) Hydrolysis
(C) Esterification
(D) Polymerization
Homologous Series
Features of Homologous Series:
Which of the following features is NOT true for all homologous series of compounds?
(A) the same functional group
(B) the same general formula
(C) similar chemical properties
(D) the same empirical formula
Isomer Count
Isomers of Butane:
How many isomers of butane, C₄H₁₀, are there?
Options:
(A) 1
(B) 2
(C) 3
(D) 4
Laboratory Techniques
Preparation of Ammonia Gas:
A suitable drying agent for the laboratory preparation of ammonia gas:
(A) calcium oxide
(B) calcium chloride
(C) anhydrous copper sulfate
(D) concentrated sulfuric acid
Preparing Compounds
Observations in Compound Reactions:
Observations when aqueous silver nitrate is added to aqueous potassium chloride:
(A) A pungent gas is evolved.
(B) A blue precipitate appears.
(C) A white precipitate appears.
(D) A brown precipitate appears.
Organic Reactions
Hydrocarbon Reactions:
Discussing reactions and products formed from hydrocarbons:
Key compounds mentioned: Ethanol, propene, and vinegar.
Conclusion of Test
The test concludes with instructions for reviewing answers.
Graphs and additional details provided for clarity in chemical properties and reactions.