C7 Hydrocarbons Flashcards
What is crude oil ?
A mixture of lots of different hydrocarbons. Meaning made up of hydrogen and carbon
How can we separate mixtures ?
Separate them into fractions based on the size of the molecules by fractional distillation.
What are the characteristics of a shorter chained hydrocarbon ?
low boiling point
very volatile
light in colour
viscosity low
Characteristics of a longer chained hydrocarbon ?
High boiling point
Not very volatile
black in colour
high viscosity
What is a homolegons
A series of compounds which have the same :
General formula
trends in physical properties and chemical
What is the equation for methane ?
C H4
What is the equation for Ethane ?
C2 H6
What is the equation for propane ?
C3 H8
Equation for butane ?
C4 H10
What is a alkane ?
They are saturated hydrocarbons
The order of the fractions in boiling points
LPG
Petrol
Kerosine
Diesel
Fuel oil
Bitumen
How does the fractioning column work ?
- The mixture is heated and vaporised
- The mixture enters the column
- As fraction rises through the column they cool and condense depending on their boiling point
Which fraction contains the longest hydrocarbon chain ?
Bitumen
Which fraction contains the shortest hydrocarbons ?
LPG
What happens to the molecules when they get bigger ?
It creates stronger forces between molecules
Why is incomplete combustion less efficient then complete combustion ?
It produces soot and carbon monoxide which is poisonous to humans
What is combustion ?
The process of burning something
Why do hydrocarbons make good fuel ?
More volatile
What conditions must be present for incomplete combustion to occur ?
Lack of presence of oxygen
What is the process of cracking ?
Converting larger hydrocarbons into shorter chained ones
Why are shorter chained alkanes more useful
Lower boing points
Describe the test for a alkane
De colourise bromine water ( orang to colourless)
with alkanes no change
Define a polymer
Lots of small alkanes joined together