Alkenes Flashcards Preview

C6.2 > Alkenes > Flashcards

Flashcards in Alkenes Deck (13):
1

What are Alkenes?

Unsaturated hydrocarbon
Contains 1 double bonded carbon

2

What are the first 3 Alkenes?

Ethene (C2H4)
Propene (C3H6)
Butene (C4H8)

3

What are the first six prefixes that relate to the amount of Carbon atoms?

Meth- (1 carbon atom)
Eth- (2)
Prop- (3)
But- (4)
Pent- (5)
Hex- (6)

4

What is the general formula for Alkenes?

C H
n 2n

5

How do you model Alkenes?

Draw carbon atoms in line first
Add correct number of bonds (remembering 1 double bond)
Add hydrogen atoms

6

What is a Functional Group?

Atom, group of atoms or type of bond that determines the chemical reactions of an organic compound

7

How do Alkenes react? Why?

Alkenes can have combustion reactions with the same products as Alkanes
They have a functional group so can take part in a wider range of reactions
Because they have a double bonded carbon, they can take part in Addition reactions

8

What are Addition reactions?

Reaction in which an atom or group of atoms combines with a molecule to form a larger molecule with no other product

9

What happens to Alkenes in Addition reactions?

Alkenes react with Bromine to form colourless 'dibromo' compounds

10

What is a word equation for an example of an Addition reaction with an Alkene?

Ethene + Bromine -> Dibromoethane

11

How is this addition reaction the basis of a test for unsaturation?

Bromine reacts with Alkenes but not Alkanes
Bromine water turns from orange-brown to colourless when mixed with Alkenes but not with Alkanes

12

What happens in Addition reactions between Alkenes and Hydrogen?

Alkenes react with hydrogen in the presence of a Nickel catalyst to form Alkanes

13

What is an example of an Addition reaction between an Alkene and Hydrogen?

Ethene + Hydrogen -> Ethane