Addition reactions of alkenes and alcohols Flashcards
What is the general formula for alkenes?
CnH2n
Name the first four alkenes
- Ethene
- Propene
- Butene
- Pentene
What must ALL alekenes have?
Double covalent bond between adjacent carbon atoms
What is the molecular formula for ethene?
C2H4
What is the molecular formula for propene?
C3H6
What is the molecular formula for butene?
C4H8
What is the molecular formula for pentene?
C5H10
Are alkenes saturated or unsaturated?
Unsaturated
Why are alkenes unsaturated?
They have 2 fewer hydrogen atoms for the same number of carbon atoms
What is it called when alkenes react with hydrogen?
Hydrogenation
What is the functional group in alkenes?
The carbon to carbon double bond
What is meant by a functional group?
The part of a molecule which determines how it reacts
What is produced when alkenes react with hydrogen?
An alkane
A not E, because it becomes saturated
What happens to alekenes when they react with hydrogen?
They become saturated
What conditions are required to react hydrogen with alkenes?
150 degrees Celcius
Nickel Catalyst
What is produced when alkenes completely combust?
They produce CO2 and Water, the same as other hydrocarbons
What happens when alkenes react with air
The carbon does not burn completely so the alkene incompletely combusts due to an insufficient supply of oxygen
This produces a smoky flame
What is the reaction between alkenes and water called?
Hydration
What state must water be in for the hydration of alkenes to occur?
Steam
What is the product of the hydration of alkenes?
Alcohol
What are the conditions required for the hydration of alkenes to take place?
300 degrees Celcius
Phosphoric acid catalyst
Water must be steam
What conditions are required for the addition reaction of halogens to alkenes?
No specific conditions
Why aren’t specific conditions required for the addition reaction between halogens and alkenes?
Alkenes react rapidly with halogens
How do you write the name of the product from the addition reaction between a halogen and an alkene?
e.g. ethene reacts with iodine
1. Take -ine and add -o = iodo
2. add di at the beginning = diiodo
3. Add the alkane counterpart of the alkene at the end (after o) = diiodoethane
= diiodoethane
Why are alkenes more reactive than alkanes?
More atoms can be easily reacted with the carbons at the double bond in an addition reaction