IGCSE Organic Chemistry Quiz

What is addition polymerisation?

• A reaction where large molecules break down

• A reaction where small molecules bond to form a long chain polymer

• A reaction where gases are released

• A reaction where water is produced

Answer explanation

Addition polymerisation is a process where small molecules, known as monomers, chemically bond together to form a long chain polymer. This distinguishes it from other reactions that involve breakdown or the release of gases or water.

Which of the following is NOT a member of the first four alcohols?

• Methanol

• Ethanol

• Propanol

• Pentanol

Answer explanation

The first four alcohols are methanol, ethanol, propanol, and butanol. Pentanol is the fifth alcohol, making it the correct choice as it is NOT a member of the first four.

What does biodegradable mean?

• Able to be broken down by water

• Able to be broken down by living organisms

• Able to be broken down by sunlight

• Able to be broken down by heat

Answer explanation

Biodegradable refers to materials that can be broken down by living organisms, such as bacteria and fungi, into natural substances. This process helps reduce waste and is essential for environmental sustainability.

What functional group do carboxylic acids contain?

• –OH

• –NH2

• –COOH

• –CH3

Answer explanation

Carboxylic acids contain the functional group –COOH, which is characterized by a carbonyl (C=O) and a hydroxyl (–OH) group. This structure is essential for their acidic properties.

What is combustion?

• The process of freezing a substance

• The burning of a substance

• The melting of a substance

• The evaporation of a substance

Answer explanation

Combustion is defined as the burning of a substance, which involves a chemical reaction with oxygen, producing heat and light. The other options refer to different physical processes, not combustion.

What is cracking?

• A process of joining small molecules

• A process of breaking down larger hydrocarbons

• A process of freezing hydrocarbons

• A process of melting hydrocarbons

Answer explanation

Cracking is a chemical process that breaks down larger hydrocarbons into smaller, more useful molecules, making the correct choice "A process of breaking down larger hydrocarbons."

What is an empirical formula?

• The largest whole number ratio of atoms

• The smallest whole number ratio of atoms

• The average number of atoms

• The total number of atoms

Answer explanation

The empirical formula represents the smallest whole number ratio of atoms in a compound, distinguishing it from the molecular formula, which may show larger ratios. Thus, the correct choice is 'The smallest whole number ratio of atoms'.

What is fermentation?

• A chemical process where glucose is broken down aerobically

• A chemical process where glucose is broken down anaerobically

• A physical process where glucose is frozen

• A physical process where glucose is melted

Answer explanation

Fermentation is a chemical process where glucose is broken down anaerobically, meaning it occurs without oxygen. This process is crucial for producing energy in certain organisms, unlike aerobic processes that require oxygen.

What is a finite resource?

• A resource that will never run out

• A resource that will one day run out

• A resource that is always renewable

• A resource that is infinite

Answer explanation

A finite resource is one that will eventually be depleted. This means it is not renewable and will run out, making 'A resource that will one day run out' the correct choice.

What is fractional distillation?

• A process to mix liquids

• A process to separate a mixture of liquids

• A process to freeze liquids

• A process to boil liquids

Answer explanation

Fractional distillation is a method used to separate a mixture of liquids based on their different boiling points, making 'A process to separate a mixture of liquids' the correct choice.