bonding and structure

Question 1

define ionic bond

Answer 1

the electrostatic attraction between positive and negative ions

Question 2

describe and explain the conductivity of ionic compounds under different states

Answer 2

doesnt conduct when a solid because the ions are fixed in a lattice and arent free to move so cant carry a charge
conducts when molten or dissolved because the ions are free to move so can carry a charge

Question 3

why are ionic compounds soluble

Answer 3

as water molecules are polar so will surround each ion

Question 4

why are some ionic compounds more soluble then others

Answer 4

greater charge difference meaning stronger attractions which is less easily overcome

Question 5

why do ionic compounds have high melting and boiling points

Answer 5

strong electrostatic attraction between negative and positive ions which requires lots of energy to overcome

Question 6

define covalent bond

Answer 6

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

Question 7

define bond enthalpy

Answer 7

a measurement of covalent bond strength

Question 8

what is a coordinate/dative covalent bond

Answer 8

a shared pair of electron in which both electrons comes fron the same atom

Question 9

give three bond angles from largest to smallest

Answer 9

bond angle between lone pairs
bond angle between a lone pair and a bonding pair
bind angle between bonding pairs

Question 10

what do lone pairs repel by and why

Answer 10

2.5 as they are closer to the nucleus and take up more space

Question 11

describe a linear shape

Answer 11

2 bp
0 lp
180 degrees

Question 12

describe trigonal planar

Answer 12

3 bp
0 lp
120 degrees

Question 13

describe tetrahedral shape

Answer 13

4 bp
0 lp
109.5 degrees

Question 14

describe triogonal pyramidal shape

Answer 14

3 bp
1 lp
107 degrees

Question 15

describe non linear shape

Answer 15

2 bp
2 lp
104.5 degrees

Question 16

describe octehedral shape

Answer 16

6bp
0lp
90 degrees

Question 17

how to tackel a explain the shape of molecule question

Answer 17

state the numbee of bp and lp
state electrons repel and try to get as far apart as possible
state lp repel more then bp or that they repel equally if no lp
state shape of molecule and bond angle

Question 18

why are chemists able to predict the shape of molecules

Answer 18

as electrons repel and the shape is determined by number of lp and bp

Question 19

define electronegativity

Answer 19

the ability of an atom to attract electrons in a covalent bond to itself

Question 20

when can you tell a bond is polar

Answer 20

if the two atoms are different elements

Question 21

how can a molecule be non polar but contain polar bonds

Answer 21

as it’s symmetrical so the dipoles cancel each other out

Question 22

how can you work out if a molecule is symmetrical

Answer 22

generally if it doesnt have any lp

Question 23

what are permanent dipole dipole interactions

Answer 23

electrostatic force of attractuon between polar molecules

Question 24

does every structure have london forces

Answer 24

no lattices dont

Question 25

describe induced dipole dipole interactions

Answer 25

unequal distribution of electrons temporary/ instantaneous dipoles induces dipoles in nearby molecules leading to attraction

Question 26

why does the strength of induced sipole interaction increase down groups

Answer 26

the number of electrons increases stronger dipoles stronger attractions

Question 27

which electronegative elements will hydrogen bonding happen with and why

Answer 27

F O N | they are the most electronegative and most dense in electrons

Question 28

give 3 reasons why water has a higher mp and boiling point to structurally similar compounds

Answer 28

hydrogen bonding provides it with stronger intermolecular forces can form up to 4 hydrogen bonds oxygen is the second most electronegative element meaning stronger hydrogen bonds

Question 29

give and explain 2 anomalous properties of ice

Answer 29

ice is less dense then water as the molecules are held apart by hydrogen bonds in an open lattice it has a higher mp then expected as hydrogen bonding provides it with stronger intermolecular forces

Question 30

what cause high surface tension in water

Answer 30

hydrogen bonding leading to a strong and flexable lattice structure

Question 31

what can polar and non polar molecules dissolve in

Answer 31

likes dissolve likes

Question 32

what are the strongest to weakest intermolecular forces

Answer 32

hydrogen bonds permanent dipole dipole london forces

Question 33

why is a p block element considered a p block element

Answer 33

its outer electron is in the p sub shell or as its highest energy electron occupies the p subs shell

Question 34

why wont all of CO2 be released from a reaction involving a solution

Answer 34

it is soluble in water