types of intermolecular forces

Question 1

what are the ions in ionic compounds held together by ?

Answer 1

strong electrostatic forces of attraction

Question 2

where do intermolecular forces of attraction act ?

Answer 2

they act in between molecules

Question 3

how strong are intermolecular forces ?

Answer 3

intermolecular forces are much weaker than covalent bonds and are easily broken by high temp

Question 4

what happens when we heat a simple molecular substance ?

Answer 4

it cause the molecules to move faster and at a certain temperature the intermolecular forces break and this allows the molecules to move away from each other

Question 5

what are the 3 types of intermolecular forces ?

Answer 5

• van der waals forces (London dispersion forces)
• permanent dipole-dipole attraction
• hydrogen bonding

Question 6

in which substances do van der waals forces occur ?

Answer 6

van der waals forces are present in all molecular substances

Question 7

why do van der waals forces occur ?

Answer 7

they occur because the electrons are constantly moving around and there will be an uneven electron distribution at any given moment in time which causes a temporary dipole within a molecule
this temporary dipole induces a temporary dipole in a neighbouring molecule and there is then an attraction between these molecules

Question 8

the bigger the molecule….?

Answer 8

the greater the van der waals forces
(more electrons= higher boiling point)

Question 9

how strong are van der waals forces ?

Answer 9

they are fairly weak because all intermolecular forces are weaker than covalent bonds

Question 10

between which molecules does permanent dipole-dipole attraction occur ?

Answer 10

between polar molecules

Question 11

which molecules are non-polar but contain polar bonds ?

Answer 11

CCl4 and CO2
- these do not have permanent dipole-dipole interactions