Question 1

A student is asked to determine the number of moles in 18 grams of water (H₂O). Given that the molar mass of water is 18 g/mol, which calculation is correct?
Correct answer: n = 18 g / 18 g/mol = 1 mol

Accepted Answer

n = 18 g / 18 g/mol = 1 mol

Question 2

Which of the following best describes the process of electrolysis in terms of its real-world application?
Correct answer: Electrolysis is used to extract metals such as aluminum from their ores.

Accepted Answer

Electrolysis is used to extract metals such as aluminum from their ores.

Question 3

A chemical reaction releases 500 J of heat energy when 10 g of a substance is heated. If the specific heat capacity is 2 J/g°C, what is the temperature change (ΔT)?
Correct answer: ΔT = 25°C

Accepted Answer

ΔT = 25°C

Question 4

Which of the following statements about acids, bases, and salts is correct?
Correct answer: A salt is formed when an acid reacts with a base.

Accepted Answer

A salt is formed when an acid reacts with a base.

Question 5

Which of the following best explains why metals are good conductors of electricity?
Correct answer: Metals have delocalized electrons that move freely throughout the structure.

Accepted Answer

Metals have delocalized electrons that move freely throughout the structure.

Question 6

A student is given a mixture of sand and salt. Which experimental technique should be used to separate the salt from the sand?
Correct answer: Dissolve the mixture in water, filter to remove sand, then evaporate the water to recover the salt.

Accepted Answer

Dissolve the mixture in water, filter to remove sand, then evaporate the water to recover the salt.

Question 7

Which of the following is a correct example of a chemical change?
Correct answer: Iron rusting when exposed to air and moisture.

Accepted Answer

Iron rusting when exposed to air and moisture.

Question 8

Which statement best describes the environmental impact of burning fossil fuels?
Correct answer: It releases greenhouse gases such as CO₂, contributing to global warming.

Accepted Answer

It releases greenhouse gases such as CO₂, contributing to global warming.

Question 9

Which of the following best describes the arrangement of particles in a solid?
Correct answer: Particles are closely packed in a fixed, regular pattern and vibrate in place.

Accepted Answer

Particles are closely packed in a fixed, regular pattern and vibrate in place.

Question 10

A student is asked to balance the following chemical equation: ___ H₂ + ___ O₂ → ___ H₂O. What are the correct coefficients?
Correct answer: 2 H₂ + 1 O₂ → 2 H₂O

Accepted Answer

2 H₂ + 1 O₂ → 2 H₂O

Question 11

Which of the following is a property of transition metals that makes them useful as catalysts in industrial processes?
Correct answer: They can change oxidation states and form complexes with reactants.

Accepted Answer

They can change oxidation states and form complexes with reactants.

Question 12

Which of the following best describes the role of stoichiometry in chemical reactions?
Correct answer: It allows chemists to calculate the quantities of reactants and products involved in a reaction.

Accepted Answer

It allows chemists to calculate the quantities of reactants and products involved in a reaction.

Question 13

A solution is tested with litmus paper and turns red. Which of the following is most likely true about the solution?
Correct answer: The solution is acidic.

Accepted Answer

The solution is acidic.

Question 14

Which of the following is a correct safety practice when heating chemicals in a laboratory?
Correct answer: Always point the mouth of a test tube away from yourself and others.

Accepted Answer

Always point the mouth of a test tube away from yourself and others.

Question 15

Which of the following best explains why carbon forms a vast number of organic compounds?
Correct answer: Carbon can form four covalent bonds, allowing for a variety of stable structures.

Accepted Answer

Carbon can form four covalent bonds, allowing for a variety of stable structures.

Question 16

A sample of gas is compressed at constant temperature. According to the kinetic theory, what happens to the pressure of the gas?
Correct answer: The pressure increases because the particles collide more frequently with the walls.

Accepted Answer

The pressure increases because the particles collide more frequently with the walls.

Question 17

Which of the following is a correct statement about the Periodic Table?
Correct answer: Elements in the same group have similar chemical properties.

Accepted Answer

Elements in the same group have similar chemical properties.

Question 18

A student is asked to analyze a colorless solution to determine if it contains chloride ions. Which test should be performed?
Correct answer: Add silver nitrate solution; a white precipitate indicates chloride ions.

Accepted Answer

Add silver nitrate solution; a white precipitate indicates chloride ions.

Question 19

Which of the following best describes the importance of data analysis in chemistry experiments?
Correct answer: It helps interpret results, identify patterns, and draw valid conclusions.

Accepted Answer

It helps interpret results, identify patterns, and draw valid conclusions.

Question 20

Which of the following is a correct application of the equation Q = mcΔT in a real-life scenario?
Correct answer: Calculating the energy required to heat water in a kettle.

Accepted Answer

Calculating the energy required to heat water in a kettle.

Overview of Cambridge IGCSE Chemistry 0620 Syllabus

Study Guide - Practice Questions

Study Guide - Flashcards