C7 & C8 - Organic Chemistry & Analysis Flashcards
Which 2 elements are hydrocarbons made from?
Carbon and Hydrogen
Draw out these alkanes and remember to add in the formula
Methane (………….)
Methane CH4
Draw out these alkanes and remember to add in the formula
Ethane (………….)
Ethane C2H6
Draw out these alkanes and remember to add in the formula
Propane (………….)
Propane C3H8
What is the equation for combustion of a hydrocarbon?
Hydrocarbon + Oxygen –> Carbon Dioxide + Water (+ Energy Released)
What are the PROPERTIES of SHORTER hydrocarbons?
- Less Viscous (they are runny)
- More Flammable
- More Volitile (more likely to turn into a gas)
- Lower boiling point (easier to boil)
What are the PROPERTIES of LONGER hydrocarbons?
- More Viscous (they are sticker and less runny)
- Less Flammable (harder to burn)
- Less Volitile (less likely to turn into a gas)
- Higher boiling point (harder to boil)
Are longer or shorter hydrocarbons more useful as fuels?
SHORTER - Because they are more flammable
What is cracking?
Long hydrocarbons can be broken up into small ones.
These can be used for fuels
This is called CRACKING
What is this process called?
Fractional Distillation
In Fractional Distillation
Which type of hydrocarbons come out from the top?
Shorter Hydrocarbons
With lower boiling points
In Fractional Distillation
Which type of hydrocarbons come out from the bottom?
Longer Hydrocarbons
With higher boiling points
In Fractional Distillation
What happens to the oil before it enters the fractionating column
It is vapourised
How do you test for
OXYGEN
Relight a glowing split
How do you test for
CARBON DIOXIDE
Bubble it though limewater and it will go cloudy
How do you test for
HYDROGEN
Squeaky Pop
Add a lit split and it should give a squeaky pop sound
In Chromatography
Why is the line drawn in pencil?
Pencil will not dissolve in the water
Pen might dissolve
In Chromatography
Why must the water be below the line
If the water is above the line, the ink will dissolve into the water and will not move up the paper
