Question 1

A sealed syringe contains 20 mL of air at room temperature. When the plunger is pushed in and the volume is halved to 10 mL, what happens to the pressure of the gas inside, assuming temperature remains constant?
Correct answer: The pressure doubles

Accepted Answer

The pressure doubles

Question 2

Which statement best explains why diamond is extremely hard while graphite is soft, even though both are forms of carbon?
Correct answer: Diamond has a giant covalent structure with each carbon atom bonded to four others, while graphite has layers of carbon atoms bonded in hexagons with weak forces between layers.

Accepted Answer

Diamond has a giant covalent structure with each carbon atom bonded to four others, while graphite has layers of carbon atoms bonded in hexagons with weak forces between layers.

Question 3

A student is asked to determine the purity of a sample of copper(II) sulfate by dissolving it in water and measuring its boiling point. Which experimental skill is primarily being assessed?
Correct answer: Interpreting data and evaluating methods

Accepted Answer

Interpreting data and evaluating methods

Question 4

Which of the following best describes the process of electrolysis in the extraction of aluminum from its ore?
Correct answer: Aluminum ions gain electrons at the cathode to form aluminum metal.

Accepted Answer

Aluminum ions gain electrons at the cathode to form aluminum metal.

Question 5

A sample contains 75% chlorine-35 and 25% chlorine-37. What is the relative atomic mass (Ar) of chlorine?
Correct answer: 35.5

Accepted Answer

35.5

Question 6

Which of the following is a correct balanced equation for the reaction between hydrochloric acid and sodium hydroxide?
Correct answer: HCl + NaOH → NaCl + H2O

Accepted Answer

HCl + NaOH → NaCl + H2O

Question 7

Which property is most likely to be observed in a substance with a giant ionic lattice structure?
Correct answer: High melting point and conducts electricity when molten

Accepted Answer

High melting point and conducts electricity when molten

Question 8

A student adds excess zinc to a solution of copper(II) sulfate. Which type of chemical reaction is this?
Correct answer: Displacement

Accepted Answer

Displacement

Question 9

Which of the following best explains why noble gases are unreactive?
Correct answer: They have a full outer shell of electrons

Accepted Answer

They have a full outer shell of electrons

Question 10

A student is asked to design an experiment to compare the rates of reaction between magnesium and hydrochloric acid at different temperatures. Which variable should be kept constant?
Correct answer: Concentration of hydrochloric acid

Accepted Answer

Concentration of hydrochloric acid

Question 11

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

Accepted Answer

Isotopes have the same number of protons but different numbers of neutrons

Question 12

Which of the following best describes the environmental impact of sulfur dioxide released from burning fossil fuels?
Correct answer: It causes acid rain, which damages buildings and aquatic life

Accepted Answer

It causes acid rain, which damages buildings and aquatic life

Question 13

Which of the following is a property of metals that makes them suitable for use in electrical wiring?
Correct answer: They are good conductors of electricity due to delocalized electrons

Accepted Answer

They are good conductors of electricity due to delocalized electrons

Question 14

Which of the following best describes the process of fractional distillation in the separation of crude oil?
Correct answer: It separates components based on their different boiling points

Accepted Answer

It separates components based on their different boiling points

Question 15

A student is given a colorless solution and asked to identify the presence of chloride ions. Which reagent should be added?
Correct answer: Silver nitrate solution

Accepted Answer

Silver nitrate solution

Question 16

Which of the following best explains why water is a good solvent for ionic compounds?
Correct answer: Water molecules are polar and can surround and separate ions

Accepted Answer

Water molecules are polar and can surround and separate ions

Question 17

Which of the following is a correct statement about acids and bases?
Correct answer: Acids donate protons (H+) and bases accept protons

Accepted Answer

Acids donate protons (H+) and bases accept protons

Question 18

A hydrocarbon burns in excess oxygen to form carbon dioxide and water. What type of reaction is this?
Correct answer: Combustion

Accepted Answer

Combustion

Question 19

Which of the following best describes the trend in reactivity of Group 1 metals as you go down the group?
Correct answer: Reactivity increases because the outer electron is further from the nucleus

Accepted Answer

Reactivity increases because the outer electron is further from the nucleus

Question 20

A student is asked to calculate the empirical formula of a compound containing 40% sulfur and 60% oxygen by mass. What is the empirical formula?
Correct answer: SO3

Accepted Answer

SO3

Overview of Cambridge IGCSE Chemistry 0620 Syllabus

Study Guide - Practice Questions

Study Guide - Flashcards