organic chemistry (p2) Flashcards
What is crude oil?
a mixture of a large number of compounds, most of which are hydrocarbon
How was crude oil formed?
from the remains of organisms that lived and died millions of years ago (mainly plankton which was buried in the mud)
Is crude oil a finite or renewable resource?
Finite
What is a hydrocarbon?
a compound made up of carbon and hydrogen only
Why type of bond joins the carbon and hydrogen atoms in a hydrocarbon
covalent bond
What is an organic compound?
compounds containing carbon atoms covalently bonded to other atoms
What is a homologous series?
a family of organic compounds with the same general formula and similar properities
What is the general formula for alkanes?
CₙH₂ₙ₊₂
What are the names of the first four members of the alkanes?
Methane
Ethane
Propane
Butane
What do the names of alkanes always end in?
-ane
How many bonds does carbon form in a compound?
four
How many bonds does hydrogen form in a compound?
1
How are the different compounds in crude oil separated?
Fractional distillation
What is a fraction?
a mixture of hydrocarbons with a similar number of carbon atoms
What are the products of fractional distillation used for?
- fuels
- starting materials for the petrochemical industry
What are the names of some fractions produced in fractional disillation?
- petrol
- diesel oil
- kerosene
- heavy fuel oil
- liquefied petroleum gases
What useful materials are produced by the petrochemical industry?
- solvents
- lubricants
- polymers
- detergents
How does the temperature of the fractionating column change as you move from bottom to top?
the temperature decreases
What happens when crude oil is heated before entering the fractionating column?
the crude oil evaporates
What happens to the crude oil vapours as they travel up the fractionating column?
- they cool and condense
- when they condense they are collected
Describe how crude oil is seperated in fractional distillation
- Crude oil is heated and it evaporates
- The crude oil vapours enter the fractionating column and travel upwards
- The temperature of the fractionating column decreases towards the top
- As the vapours travel up they cool and condense at different temperatures depending on their boiling points
Where are the long chain hydrocarbons collected in fractional distillation?
At the bottom of the fractionating column
Where are the short chain hydrocarbons collected in fractional distillation?
At the top of the fractionating column