Addition reactions of alkenes

Question 1

What is an addition reaction?

Answer 1

A reaction where a reactant is added to an unsaturated molecule to make one saturated molecule

Question 2

What are the conditions to form an alkane?

Answer 2

Hydrogen and a Nickel catalyst

Question 3

What are the conditions to form a haloalkane?

Answer 3

A halogen

Question 4

What are the conditions to form a non-symmetrical haloalkane?

Answer 4

Hydrogen halide - e.g. HBr

Question 5

What are the conditions to form an alcohol?

Answer 5

Steam and a phosphoric acid catalyst

Question 6

What is an electrophile?

Answer 6

An atom or a pair of electrons which is attracted to an electron-rich centre where it accepts a pair of electrons to form a new covalent bond

Question 7

How do you draw the mechanism for electrophillic addition?

Answer 7

1. A curly arrow from double bond to delta positive atom in electrophile and curly arrow from bond between electrophile to delta negative atom (show partial charges)
2. Delta positive atom is now bonded and double bond is gone. curly arrow from electrophile (lone pair of electrons and charge shown) to unbonded carbon (with + sign shown)

Question 8

What happens in electrophillic addition?

Answer 8

The pi bonds breaks between the carbons in the C=C bond and a new bond forms.

Question 9

What type of fission occurs in electrophillic addition?

Answer 9

Heterolytic