chapter 6

Question 1

what are the features of a linear shape

Answer 1

a linear shape has 2 electron areas and has 180 degree bond angle

Question 2

what are the features of a trigonal planar shape

Answer 2

a trigonal planar shape has 3 electron regions and has 120 degree bond angle between atoms

Question 3

what are the features of a tetrahedral shape

Answer 3

a tetrahedral shape has 4 electron regions and a 109.5 degree angle between atoms

Question 4

what are the features of an octahedral shape

Answer 4

has 6 electron regions and has 90 degree bond angles

Question 5

what is the electron pair repulsion theory

Answer 5

this theory suggests that as electrons repel each other the arrangement of electrons minimises the repulsion and so the bonded atoms stay in a definite shape.

Question 6

what happens of there are lone pairs of electrons

Answer 6

the molecules form weird shapes

Question 7

what are the features of a trigonal bi pyramidal

Answer 7

5 electron regions 2 90 degree bond angles and 3 120 degree bond angles

Question 8

what are the features of a non linear shape

Answer 8

2 BP 2 LP and an 104.5 degree bond angles

Question 9

what are the features of a trigonal bi pyramidal molecule

Answer 9

1LP 3 BP and 10 7degree bond angles

Question 10

what are the 3 types of intermolecular forces

Answer 10

London forces , permanent dipole-dipole interactions and hydrogen bonding

Question 11

what is the strongest intermolecular forces

Answer 11

hydrogen bonding

Question 12

what is the weakest inter-molecular forces

Answer 12

London forces

Question 13

what is the second strongest intermolecular force

Answer 13

permanent dipole-dipole interactions

Question 14

what are London forces (induced dipole dipole interactions)

Answer 14

weak intermolecular forces
exist in all molecules
movement of electrons produces a changing dipole in a molecule
can be attracted to the opposite charged dipole

Question 15

what are permanent dipole dipole interactions

Answer 15

forces of attraction that appear between permanently differently charged polar molecules

Question 16

what is hydrogen bonding

Answer 16

hydrogen bonding is the attraction between a slightly negative hydrogen and another slightly positive element or an element ith lone pairs of electrons

Question 17

what are the anomalous properties of water

Answer 17

solid ice is less dense then the liquid water relatively high boiling , melting points for a covalently bonded molecule relatively high surface tension and viscocity

Question 18

why is ice less dense then water

Answer 18

ice is less dense then water as with 2 lone pairs on the oxygen and 2 hydrogens each water molecule can form 4 hydrogen bonds that form an open tetrahedral shape.This has lots of holes that decrease the density of the water when ice melts the lattice collapses

Question 19

why has water got a relatively high melting boiling point

Answer 19

Water contains all 3 types of intermolecular bonds (London forces, induced and permanent dipole dipole interactions)