Paper 1 - Alkenes and Alkanes Flashcards
Describe the reactions of alkenes to produce dibromoalkenes.
- The reaction between bromine and alkene is an example of an addition reaction
- Atoms of a simple molecule such as bromine add across the C=C double bond
What condition is required for a substitution reaction?
UV light/radiation
How can Bromine water be used to distinguish between an Alkene or an Alkane?
- Add hydrocarbon to Bromine water
- If the hydrocarbon is an Alkene, double is broken and the solution turns
from orange to colourless - If the hydrocarbon is an Alkane, the solution remains orange
What is the displayed formula of ethane?
Draw it then google it
What is the displayed formula of propane?
Draw it then google it
What is the displayed formula of butane?
Draw it then google it
What is the displayed formula of pentane?
Draw it then google it
What is the displayed formula of propene?
Draw it then google it
What is the displayed formula of butene?
Draw it then google it
Describe the reactions of Alkanes with Halogens in the presence of UV light
- Substitution reaction
- One Halogen atom is substituted for a hydrogen atom
What is the general formula of Alkenes?
CnH2n
What is the general formula of Alkanes?
CnH2n+2
What functional group do alkenes contain?
\ /
C=C
/ \
Why is cracking necessary in terms of supply and demand for different fractions?
- Shorter chain hydrocarbons are in much higher demand than longer chain hydrocarbons
- Cracking produces more short chain hydrocarbons to supply the demand
Why are alkenes classified as unsaturated hydrocarbons?
- They contain a double bond
- They contain carbon and hydrogen atoms ONLY
