Question 1

Which of the following best explains why ionic compounds generally have high melting points?
Correct answer: They are made up of a lattice of oppositely charged ions held together by strong electrostatic forces.

Accepted Answer

They are made up of a lattice of oppositely charged ions held together by strong electrostatic forces.

Question 2

A student is asked to determine the relative atomic mass of chlorine using the following data: 75% of chlorine atoms have a mass of 35, and 25% have a mass of 37. What is the relative atomic mass of chlorine?
Correct answer: 35.5

Accepted Answer

35.5

Question 3

Which of the following laboratory practices is most important for ensuring safety when heating a substance in a test tube?
Correct answer: Pointing the open end of the test tube away from yourself and others.

Accepted Answer

Pointing the open end of the test tube away from yourself and others.

Question 4

Which statement best describes the kinetic particle theory as it applies to gases?
Correct answer: Particles in a gas move randomly and rapidly, with negligible forces between them.

Accepted Answer

Particles in a gas move randomly and rapidly, with negligible forces between them.

Question 5

A solution of hydrochloric acid is titrated with sodium hydroxide. Which of the following best describes the chemical reaction taking place?
Correct answer: A neutralization reaction producing a salt and water.

Accepted Answer

A neutralization reaction producing a salt and water.

Question 6

Which of the following is a correct example of a covalent compound and its typical property?
Correct answer: Water; does not conduct electricity in pure form.

Accepted Answer

Water; does not conduct electricity in pure form.

Question 7

A student is designing an experiment to investigate the effect of temperature on the rate of a chemical reaction. Which variable should be kept constant to ensure a fair test?
Correct answer: The concentration of the reactants.

Accepted Answer

The concentration of the reactants.

Question 8

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

Accepted Answer

They contain delocalized electrons that move freely throughout the structure.

Question 9

During electrolysis of molten sodium chloride, which products are formed at the cathode and anode, respectively?
Correct answer: Sodium at the cathode, chlorine at the anode.

Accepted Answer

Sodium at the cathode, chlorine at the anode.

Question 10

Which of the following best describes the environmental impact of excessive use of nitrogen-based fertilizers?
Correct answer: They cause eutrophication, leading to algal blooms in water bodies.

Accepted Answer

They cause eutrophication, leading to algal blooms in water bodies.

Question 11

A sample contains 2.0 moles of oxygen molecules (O2). How many oxygen atoms are present in the sample?
Correct answer: $$1.2 × 10^24$$ atoms

Accepted Answer

$$1.2 × 10^24$$ atoms

Question 12

Which of the following best illustrates the use of stoichiometry in a real-world context?
Correct answer: Calculating the amount of reactants needed to produce a specific mass of product in industrial synthesis.

Accepted Answer

Calculating the amount of reactants needed to produce a specific mass of product in industrial synthesis.

Question 13

Which of the following is a correct statement about isotopes?
Correct answer: Isotopes of an element have the same number of protons but different numbers of neutrons.

Accepted Answer

Isotopes of an element have the same number of protons but different numbers of neutrons.

Question 14

A student observes that a reaction mixture becomes colder as the reaction proceeds. Which type of reaction is most likely occurring?
Correct answer: Endothermic reaction

Accepted Answer

Endothermic reaction

Question 15

Which of the following best describes the trend in reactivity of Group 1 metals as you move down the group in the Periodic Table?
Correct answer: Reactivity increases because the outer electron is more easily lost.

Accepted Answer

Reactivity increases because the outer electron is more easily lost.

Question 16

Which of the following is the best example of applying chemical analysis in a medical context?
Correct answer: Using chromatography to identify drugs in a patient's blood sample.

Accepted Answer

Using chromatography to identify drugs in a patient's blood sample.

Question 17

A student is asked to plan an experiment to test the effect of concentration on the rate of a reaction. Which of the following is the most appropriate hypothesis?
Correct answer: The rate of reaction increases as the concentration of reactants increases.

Accepted Answer

The rate of reaction increases as the concentration of reactants increases.

Question 18

Which of the following best explains why carbon dioxide is considered a greenhouse gas?
Correct answer: It absorbs infrared radiation and traps heat in the atmosphere.

Accepted Answer

It absorbs infrared radiation and traps heat in the atmosphere.

Question 19

Which of the following is a correct statement about acids, bases, and salts?
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 20

Which of the following best demonstrates the importance of safe laboratory practice?
Correct answer: Wearing safety goggles to protect eyes from chemical splashes.

Accepted Answer

Wearing safety goggles to protect eyes from chemical splashes.

Overview of Cambridge IGCSE Chemistry 0620 Syllabus

Study Guide - Practice Questions

Study Guide - Flashcards