Addition Reactions of Alkenes

What is an addition reaction?

A reaction in which two molecules combine to form one product.

Why do alkenes undergo addition reactions?

Their carbon–carbon double bond can react with other substances.

What happens to the C

C bond during an addition reaction?

What is hydrogenation?

The addition of hydrogen across a carbon–carbon double bond.

What is formed when hydrogen reacts with an alkene?

An alkane.

What is the word equation for hydrogenation of ethene?

Ethene + hydrogen → ethane.

What is the symbol equation for hydrogenation of ethene?

C₂H₄ + H₂ → C₂H₆.

What catalyst is commonly used for hydrogenation?

Nickel.

Why is hydrogenation useful?

It converts unsaturated compounds into saturated compounds.

What is hydration of an alkene?

The addition of water across a carbon–carbon double bond.

What is formed when steam reacts with ethene?

Ethanol.

What is the word equation for hydration of ethene?

Ethene + steam ⇌ ethanol.

What is the symbol equation for hydration of ethene?

C₂H₄ + H₂O ⇌ C₂H₅OH.

What catalyst is used in the industrial hydration of ethene?

Phosphoric acid.

What happens when an alkene reacts with a halogen?

A halogen atom adds to each carbon of the former double bond.

What is formed when ethene reacts with bromine?

1,2-dibromoethane.

What happens when an alkene reacts with hydrogen chloride?

A chloroalkane is formed.

What is the word equation for ethene reacting with hydrogen chloride?

Ethene + hydrogen chloride → chloroethane.

Why are addition reactions important in organic chemistry?

They allow useful compounds to be manufactured from alkenes.