s&r topic 7

Question 1

what 2 things are needed for a reaction to occur

Answer 1

molecules must collide with

• correct orientation
• sufficient energy

Question 2

how do molecules overcome electrostatic repulsion

Answer 2

• thru dipoles, lone pairs or charged molecules, if these interactions overcome the repulsion
• favourable orbital interactions overcome repulsion
• orbitals must be close enough in energy for reaction to occur

Question 3

describe what a nucleophile is

Answer 3

nucleus/positive charge loving species

a negatively charged species or neutral species with a high energy orbital HOMO where electrons are donated from
or an area of electron density, pi and sigma bonds, lone pairs etc

donates electrons

Question 4

describe what an electrophile is

Answer 4

electron/negative charge loving species

a positively charged species or a neutral species with a an empty anti-bonding orbital LUMO into which electrons are accepted

accepts electrons

Question 5

what do curly arrows represent in a mechanism?

what direction is it

Answer 5

curly arrows show movement of electrons
from nucleophile to electrophile

from negative to positive

Question 6

where does the nucleophile attack

how many curly arrows are required for this attack

Answer 6

nucleophile attacks the anti-bonding orbital (LUMO)

2 curly arrows required

• one from nucleophile to one atom where the bond is breaking
• on from the bond to another atom where the bond is breaking