Reactions of alkenes Flashcards Preview

AQA Chemistry (14, Alkenes) > Reactions of alkenes > Flashcards

Flashcards in Reactions of alkenes Deck (12):

What is the reaction between ethene and air?

ethene + oxygen ---> carbon dioxide and water


What species of reaction is the primary one when it comes to alkenes?

Electrophilic additions


Why are the alkenes more likely to undergo electrophilic addition reactions?

The carbon-carbon double bonds provides an area of high electron density in which attracts electrophiles. The electrophiles will then take two of the four electrons in the double bond and thus undergoing electrophilic addition


What is an electrophile?

An electron pair acceptor


What are electrophiles made from?

Positively charged ions or are slightly delta positive in a compound


As the electrophile accepts the pair of electrons from the c-c double bond what is formed on the hydrocarbon chain?

a carbocation (a positive carbon ion)


What kind of ion forms a bond with the carbocation (a positively charged carbon ion)

A negatively charged ion


Which is more electronegative, the hydrogen or the halogen in this compound? H-Br

The halogen (bromine) H+-Br-


Draw the mechanism for the reaction of ethene with hydrogen bromide

Check page 220


Which atom acts as the electrophile out of this compound? H-Br

H (hydrogen acts as the electrophile)


What is meant by this statement? The bond between the hydrogen and bromine breaks heterolytically?

Both the electrons from the shared pair in the bond go to the bromine.


Why do the electrons between the hydrogen and bromine atom break heterolytically?

Because the bromine atom is more electronegative than hydrogen