bonding and structure

Question 1

what is the definition of a covalent bond?

Answer 1

the strong electrostatic attraction between a shared pair of electrons and the nuclei of the bonded atoms

Question 2

what is a valence electron?

Answer 2

an electron on the outer shell

Question 3

what is a dative covalent bond?

Answer 3

a dative bond is a covalent bond where only one of the bonded atoms donates both electrons being shared

Question 4

what does a stick in a displayed formula represent?

Answer 4

a covalent bond

Question 5

how many degreees does a lone pair change the bond angle by?

Answer 5

2.5°

Question 6

4 bonding pairs and no lone pairs?

Answer 6

tetrahedral
bond angles of 109.5°

Question 7

3 bonding pairs and 1 lone pair?

Answer 7

pyramidal
bond angles of 107°

Question 8

2 bonding pairs and 2 lone pairs?

Answer 8

v-shaped
104.5°

Question 9

3 bonding pairs?

Answer 9

trigonal planar
120°

Question 10

2 bonding pairs?

Answer 10

linear
180°

Question 11

6 bonding pairs?

Answer 11

octahedral
90°

Question 12

what are the election repulsion rules?

Answer 12

lone pairs repel more than bonded pairs

Question 13

what are the election repulsion rules?

Answer 13

lone pairs repel more than bonded pairs

Question 14

give the order of strength of intermolecular forces

Answer 14

hydrogen bonding > permanent dipole - dipole > induced dipole-dipole

Question 15

why does an induced dipole-dipole interaction increase in strength?

Answer 15

more electrons/larger molecule size or less branched carbon chains

Question 16

what is electronegativity?

Answer 16

the ability of an atom to attract the bonding elections in a covalent bond

Question 17

define a polarbond

Answer 17

the convent bond between atoms with different electronegativity

Question 18

define a hydrogen bond

Answer 18

the intermolecular force between the lone pair of a N, O or F of an NH, OH or FH with the H atom of NH, OH or FH in a neighbouring molecule

Question 19

2 bonding pairs and 1 lone pair?

Answer 19

v-shaped
117.5

Question 20

define a polar molecule

Answer 20

an unsymmetrical molecule whose dipoles don’t cancel out

Question 21

what are 2 anomalous properties of water?

Answer 21

1. a higher than expected melting and boiling point
2. solid water is less dense than liquid water

Question 22

why is solid water less dense than liquid water?

Answer 22

hydrogen bonding holds water molecules in an open lattice

Question 23

why does water have a higher than expected boiling point?

Answer 23

strong hydrogen bonding requires a lot of energy to break the intermolecular forves

Question 24

what is ionic bonding?

Answer 24

the strong electrostatic attraction between oppositely charged ions

Question 25

why do solid ionic substances not conduct?

Answer 25

the ions are fixed in a lattice and cannot move

Question 26

how do aqueous and molten ionic substances conduct electricity?

Answer 26

the ions are free to move

Question 27

what is metallic bonding?

Answer 27

the strong electrostatic attraction between positive ions and delocalised electrons

Question 28

how do metals conduct electricity?

Answer 28

delocalised electrons can move and conduct electricity