Popular Exam Questions & Answers
IGCSE Chemistry 0620
Credit: Mr Khing YT
Chapter 1: The Particular Nature of Matter
1)
Define a Compound [1]
-
When two or more elements are combined together
2)
Define a Molecule [1]
-
Two or more atoms are bonded together
3)
Define Element [2]
-
Substance that cannot be broken down into anything simpler
-
Substance that contains only one type of atom
4)
Explain why nitrogen gas diffuses faster than chlorine gas [2]
-
Nitrogen has a smaller relative molecular mass/Mr
-
Therefore Nitrogen Molecules move faster than chlorine molecules
5)
Explain why a gas diffuses faster at a higher temperature [2]
-
At higher temperature, molecules move faster due to having more kinetic energy
6)
What term describes the random movement of dust particles [1]
-
Brownian motion
7)
Identify the particles in the air which cause the random movement of dust
particles [2]
-
Nitrogen
molecules
or Oxygen
molecules
[1 Mark for
the element and 1 Mark for
mentioning molecule]
8)
Explain why the dust particles move in this way [2]
-
Dust particles collide with nitrogen or oxygen
molecules
-
Therefore the dust particles move randomly resulting in brownian motion
1 Chapter 2: Experimental T echniques
1)
Define a Mixture
-
Two or more substances are not chemically combined
2)
What is the method of separation that can be used to obtain water from salt
solution? [1]
-
Simple Distillation
3)
Which method would be most suitable to obtain crystals from an aqueous
solution of Copper(II) Sulfate [1]
-
Crystallization
4)
How could the purity of the ethanol collected be checked? [2]
-
Determining the melting point and boiling point
5)
How to separate and purify amino acids/glucose/color dye [1]
-
Chromatography
6)
What are the solvent that can be used during chromatography [2]
-
Water
-
Organic solvent (ethanol)
7)
Why does the sample stay on the baseline/not move during
chromatography? And how to deal with this? [2]
-
It is insoluble in the solvent
-
Therefore use another solvent
8)
How to separate nitrogen from a mixture of nitrogen and oxygen? [3]
-
Turn the mixture into a liquid
-
Use Fractional Distillation
-
Based on dif ferent boiling points
2 Chapter 3: Atoms, Element & Compounds
1)
Define an Ion [1]
-
Group of atoms which has gained or lost electrons
2)
Define the Atomic Number [1]
-
Number of protons in one atom of an element
3)
Define the Nucleon Number [1]
-
Number of neutrons and protons in one atom of an element
4)
Define the proton number [1]
-
The number of protons in an atom
5)
Define the relative atomic mass/Mr [1]
-
Average mass of an atom compared to an atom of carbon
6)
What is a covalent bond?
-
A shared pair of electron
-
Between two atoms
-
Happens between Non-metals
7)
What is Ionic bonding? [2]
-
The electrostatic forces of attraction
-
Between oppositely charged ions
-
Happens between Metals & Non-metals
8)
Describe what happens in terms of electron loss and gain when potassium
reacts with iodine [2] (This answers applies to all types of ionic structure
just state the correct electron movement from metal and non metal and
how many electrons are transferred)
-
Movement of electron from potassium to iodine
-
One electron is transferred
9)
Define an isotope [2]
-
Atoms of the same element
-
With dif ferent number of neutrons and same number of protons
3
IGCSE Chemistry 0620
Credit: Mr Khing YT
Chapter 1: The Particular Nature of Matter
1)
Define a Compound [1]
-
When two or more elements are combined together
2)
Define a Molecule [1]
-
Two or more atoms are bonded together
3)
Define Element [2]
-
Substance that cannot be broken down into anything simpler
-
Substance that contains only one type of atom
4)
Explain why nitrogen gas diffuses faster than chlorine gas [2]
-
Nitrogen has a smaller relative molecular mass/Mr
-
Therefore Nitrogen Molecules move faster than chlorine molecules
5)
Explain why a gas diffuses faster at a higher temperature [2]
-
At higher temperature, molecules move faster due to having more kinetic energy
6)
What term describes the random movement of dust particles [1]
-
Brownian motion
7)
Identify the particles in the air which cause the random movement of dust
particles [2]
-
Nitrogen
molecules
or Oxygen
molecules
[1 Mark for
the element and 1 Mark for
mentioning molecule]
8)
Explain why the dust particles move in this way [2]
-
Dust particles collide with nitrogen or oxygen
molecules
-
Therefore the dust particles move randomly resulting in brownian motion
1 Chapter 2: Experimental T echniques
1)
Define a Mixture
-
Two or more substances are not chemically combined
2)
What is the method of separation that can be used to obtain water from salt
solution? [1]
-
Simple Distillation
3)
Which method would be most suitable to obtain crystals from an aqueous
solution of Copper(II) Sulfate [1]
-
Crystallization
4)
How could the purity of the ethanol collected be checked? [2]
-
Determining the melting point and boiling point
5)
How to separate and purify amino acids/glucose/color dye [1]
-
Chromatography
6)
What are the solvent that can be used during chromatography [2]
-
Water
-
Organic solvent (ethanol)
7)
Why does the sample stay on the baseline/not move during
chromatography? And how to deal with this? [2]
-
It is insoluble in the solvent
-
Therefore use another solvent
8)
How to separate nitrogen from a mixture of nitrogen and oxygen? [3]
-
Turn the mixture into a liquid
-
Use Fractional Distillation
-
Based on dif ferent boiling points
2 Chapter 3: Atoms, Element & Compounds
1)
Define an Ion [1]
-
Group of atoms which has gained or lost electrons
2)
Define the Atomic Number [1]
-
Number of protons in one atom of an element
3)
Define the Nucleon Number [1]
-
Number of neutrons and protons in one atom of an element
4)
Define the proton number [1]
-
The number of protons in an atom
5)
Define the relative atomic mass/Mr [1]
-
Average mass of an atom compared to an atom of carbon
6)
What is a covalent bond?
-
A shared pair of electron
-
Between two atoms
-
Happens between Non-metals
7)
What is Ionic bonding? [2]
-
The electrostatic forces of attraction
-
Between oppositely charged ions
-
Happens between Metals & Non-metals
8)
Describe what happens in terms of electron loss and gain when potassium
reacts with iodine [2] (This answers applies to all types of ionic structure
just state the correct electron movement from metal and non metal and
how many electrons are transferred)
-
Movement of electron from potassium to iodine
-
One electron is transferred
9)
Define an isotope [2]
-
Atoms of the same element
-
With dif ferent number of neutrons and same number of protons
3
