Hydrocarbons

Question 1

Hydrocarbons

Answer 1

Made of hydrogen and carbon only, Balancing reactions: carbon —> hydrogen —> oxygen

Question 2

Types of hydrocarbons

Answer 2

Types: Aliphatic (straight chain), Alicyclic (ring)- not in course, Aromatic (benzene, C6H6)

Question 3

Types of aliphatics

Answer 3

Alkane- Saturated (single bonds), CnH2n+2, Alkene- unsaturated, CnH2n, Alkyne- unsaturated, triple bond (not in course)

Question 4

Alkanes properties

Answer 4

Structural isomers (same number of carbons)
Physical properties: Low melting and boiling point- as chain length increases (larger surface area), melting/boiling point increases due to stronger dispersion forces, Low density- as chain length increases, density increases, Insoluble in water as they are non-polar and water is polar
Chemical properties: Undergo combustion reactions- complete produces CO2 and lots of energy, incomplete produces CO, Substitution reactions- swap hydrogen for halogen, use a catalyst of UV light

Question 5

Alkenes properties

Answer 5

Structural and geometric isomers,
Physical properties (same as all covalent molecules are the same): Low melting and boiling point- as chain length increases (larger surface area), melting/boiling point increases due to stronger dispersion forces, Low density- as chain length increases, density increases, Insoluble in water as they are non-polar and water is polar
Chemical properties:
Undergo combustion reactions, Addition reactions- breaks double bond

Question 6

Aromantic (benzene)

Answer 6

Each carbon is covalently bonded to 2 carbons and 1 hydrogen, 4th electron is delocalised allowing it to move freely between orbitals

Question 7

Aromantic (benzene) properties

Answer 7

Physical properties: Can’t conduction electricity as it is a discrete molecule, Low melting and boiling point however high considering it’s a small molecule because it has a high surface area allowing molecules to get closer together, increasing dispersion forces, Higher density then expected due to molecules being able to get close, Insoluble in water
Chemical properties: Combustion reactions, Substitution reactions

Question 8

Alcohol group

Answer 8

Hydroxyl group (-OH), suffix- ol

Question 9

Aldehydes group

Answer 9

Carbonyl group (-CHO with carbon-oxygen double bond), suffix- al, always on carbon 1

Question 10

Ketone group

Answer 10

Carbonyl group (-CO-), suffix- one

Question 11

Carboxylic acid group

Answer 11

Carboxyl group (-COOH), suffix- oic acid, always on carbon 2

Question 12

Esters group

Answer 12

Alkyl group attached to oxygen, suffix- oate, always on carbon 1