Bonding And Structure

Question 1

Ionic bond definition

Answer 1

Strong electrostatic force of attraction between oppositely charged ions

Question 2

Physical properties of ionic compounds

Answer 2

High melting boiling points - giant ionic lattice strong electrostatic forced between oppositely charged ions

Electrical conductivity only when molten as free ions to move

Solubility - dissolve in water

Question 3

Covalent bond definition

Answer 3

Sharing pairs of electrons between 2 non metal atoms

Question 5

What is a co ordinate bond

Answer 5

When one atom provides both the electrons needed to form covalent bond ( donates lone pair of electrons to vacant orbital )

Question 6

2 Bp 0 Lp angle and Name? Arrangement as well

Answer 6

Question 7

3 bp 0 lp angle and Name and arrangement

Answer 7

Question 8

4 Bp 0 Lp angle and name and arrangement

Answer 8

Question 9

3 bp 1 lp angle and name and arrangement

Answer 9

Question 10

2 bp 2 lp angle and name and arrangement

Answer 10

Question 11

6 bp 0 lp angle and name and arrangement

Answer 11

Question 12

What does lone pair reduce the angle by ?

Answer 12

2.5

Question 13

Describe the electron pair repulsion theory

Answer 13

LP LP repulsion > BP LP repulsion > BP BP repulsion

Question 14

What is electronegativity

Answer 14

Ability of an atom to attract a pair of electrons in a covalent bond

Question 15

What does the electronegativity depend on

Answer 15

Number of protons (greater = higher )
Atomic radius (smaller = higher )
Number of principle energy levels (fewer= higher)

Question 16

What is a polar bond

Answer 16

A covalent bond in which there is a unequal share of electrons due to differing electronegativity of the atoms involved

Question 17

What will there be if there is a difference in electronegativity

Answer 17

Polarity

Question 18

What is the polarity if atoms in a bond are same

Answer 18

Bond is non polar

Question 19

Delta - delta + where do they go

Answer 19

Delta - goes on more electronegative atom
Delta + less electronegative

Question 20

What happens to dipoles when a molecule has polar bonds but they aren’t polar molecules

Answer 20

Symmetrical so dipoles cancel out

Question 21

Is a molecule polar if it’s asymmetric (not symmetric )

Answer 21

Yes

Question 22

What are the 3 intermolecular forces in order of weakest to strongest

Answer 22

London forces PDD and hydrogen bonding

Question 23

What are London forces (induced dipole dipole)

Answer 23

A temporary dipole in one molecule induced a dipole in another molecule there is a attraction between a delta + on one molecule and a delta - in adjacent

Question 24

What affects strength of London forces

Answer 24

Size / mr of molecule

Surface area contact

Question 25

What are PDD forces ( permanent dipole dipole )

Answer 25

Only in polar molecules when there is a difference in electronegativity between the atoms , attraction between delta + and delta - on adjacent molecule

Question 26

Where does hydrogen bonding occur and why

Answer 26

Only occurs in polar molecules with hydrogen directly bonded to N O F one of them because they are most electron negative

Question 27

What is hydrogen bonding describe it and give diagram features

Answer 27

Big diff in electronegativity between attains do hydrogen and atoms N O F so they make hydrogen delta + (very) so lone pair on neighbouring molecule containing N O or F is attracted to hydrogen Features: Partial charges Lone pairs Hydrogen bond shown

Question 28

Why is ice less dense than liquid water

Answer 28

In ice water molecules further apart than liquid so more gaps between molecules

Question 29

Why does water have anomalously high boiling point

Answer 29

Due to presence of hydrogen bonds