Organic Chemistry

Question 1

What are hydrocarbons:

Answer 1

Hydrocarbons are compounds that contain hydrogen and carbon atoms only.

Question 2

Crude oil is an important source of:

Answer 2

fuels such as petrol, diesel, kerosene, heavy fuel oil and liquefied petroleum gases
feedstock for the petrochemical industry

Question 3

Other useful substances made from compounds found in crude oil include:

Answer 3

solvents

lubricants

detergents

Question 4

alkanes:

Answer 4

have the same general formula differ by CH2 in molecular formulae from neighbouring compounds
show a gradual variation in physical
properties, such as their boiling points have similar chemical properties

Question 5

The general formula for the alkanes is:

Answer 5

CnH2n+2

Question 6

During the fractional distillation of crude oil:

Answer 6

heated crude oil enters a tall
fractionating column, which is hot at the bottom and gets cooler towards the top vapours from the oil rise through the column vapours condense when they become cool enough liquids are led out of the column at different heights

Question 7

hydrocarbons called
alkanes have similarilar:

Answer 7

numbers of hydrogen and carbon atoms in their
molecules

boiling points
ease of
ignition
viscosity

Question 8

hydrocarbon molecules are broken down into smaller, more useful hydrocarbon molecules, some of which are unsaturated:

Answer 8

the original starting hydrocarbons are alkanes the products of cracking include alkanes and alkenes, members of a different homologous series

Question 9

hydrocarbon molecules are broken down into smaller, more useful hydrocarbon molecules, some of which are unsaturated:

Answer 9

the original starting hydrocarbons are alkanes the products of cracking include alkanes and alkenes, members of a different homologous series