Introduction to Alkenes and Cracking of Alkanes

The video tutorial covers the structure and properties of alkenes, including their ability to form double bonds and their general formula. It explains how alkenes are unsaturated hydrocarbons and can undergo combustion, often resulting in incomplete combustion. The video also details how alkenes react with other elements through addition reactions. The process of cracking larger hydrocarbons into smaller, more useful ones is described, highlighting both steam and catalytic cracking methods.

What is the general formula for alkenes?

• CNH2N

• C2NH2

• C2H4

• C2H2N

Why are alkenes considered unsaturated?

• They have more hydrogen atoms than alkanes.

• They contain double carbon-carbon bonds.

• They have single carbon-carbon bonds.

• They do not react with other elements.

What is a common product of incomplete combustion of alkenes?

• Methane

• Carbon monoxide

• Carbon dioxide

• Water

What happens during the addition reaction of alkenes?

• Atoms are removed from the molecule.

• Atoms are added across the double bond.

• The molecule becomes saturated with oxygen.

• The molecule loses hydrogen atoms.

Which compound is formed when a propane molecule reacts with chlorine?

• Chloropropanol

• Chloropropene

• Dichloropropane

• Propane chloride

What is the purpose of cracking in hydrocarbons?

• To increase the size of hydrocarbons

• To convert alkenes into alkanes

• To break down large hydrocarbons into smaller ones

• To remove impurities from hydrocarbons

What are the two methods of cracking mentioned?

• Steam and catalytic cracking

• Hydro and pyro cracking

• Thermal and pressure cracking

• Chemical and physical cracking