Bonding And Structure

Question 1

Why are ionic compounds hard?

Answer 1

Strong electrostatic attraction between the cations and anions which hold the ions in fixed positions

Question 2

What is the definition of ionic bonding?

Answer 2

An ionic bond is the strong electrostatic attraction between anions and cations

Question 3

Why do ionic compounds not conduct electricity when solid?

Answer 3

The ions are fixed in a giant lattice. They cannot move and carry charge

Question 4

What are ionic compounds?

Answer 4

Ionic compounds are giant structures with strong electrostatic attraction between cations and anions which are held in place in a fixed structure by these forces

Question 5

Why do ionic compounds conduct electricity when molten or in solution?

Answer 5

The ionic bonds are broken and the ions are free to move and carry charge

Question 6

What is the definition of covalent bonding?

Answer 6

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

Question 7

Why do ionic compound solids have high melting and boiling points?

Answer 7

Strong electrostatic attraction between cations and anions which needs a lot of energy to overcome

Question 8

Why does non polar simple covalent not dissolve in water?

Answer 8

Water is polar. There is no attraction between polar water molecules and non polar molecules

Question 9

Why does polar simple covalent dissolve in water?

Answer 9

The delta H+ water is attracted to the delta - of polar molecule and visa versa

Question 10

Why do covalent compounds not conduct electricity?

Answer 10

No electrons or ions that are free to move

Question 11

Why do ionic compounds dissolve in water?

Answer 11

Water is polar the slightly positive part of a water molecule attracts anions and the slightly negative part attracts cations

Question 12

Why do simple covalent molecules have a low mp and Bp?

Answer 12

The intermolecular forces between molecules are weak and not much energy is needed to overcome them

Question 13

What is dative covalent bonding?

Answer 13

A special form of covalent bonding where both electrons come from only one atom and none come from the other

Question 14

How do you predict the shape of a molecule?

Answer 14

Total number of pairs on central atom
How many bonding
How many lone

Question 15

What is the bond angle and shape of SF6?

Answer 15

90 degrees octahedral

Question 16

Why are giant covalent solids with a very high mp?

Answer 16

There are many strong covalent bonds throughout the 3D lattice which require a lot of energy to break

Question 17

How much does a lone pair reduce bond angle by?

Answer 17

2.5 degrees

Question 18

What is the bond angle and shape of NH3?

Answer 18

107 degrees pyramidal

Question 19

Why are metallic bonded items strong?

Answer 19

Strong electrostatic attraction between delocalised electrons and positive ions holds the ions in a fixed positions in the lattice

Question 20

What is the bond angle and shape of Bf3?

Answer 20

120 degrees and triginal planar

Question 21

Name three giant covalent structures

Answer 21

Silicon dioxide diamond graphite

Question 22

What is a permanent dipole dipole?

Answer 22

Polar molecules will attract each other

Question 23

What is the bond angle and shape of BeCl2v?

Answer 23

180 degrees linear

Question 25

What is the definition of electronegativity?

Answer 25

The ability of an atom to attract the bonding pair electrons in a covalent bond

Question 26

What is the two things needed to be a polar molecule?

Answer 26

Non symmetrical

Dipoles

Question 27

Where do intermolecular forces occur?

Answer 27

Simple covalent

Question 28

Why are metallically bonded items melleable/ductile?

Answer 28

When the ions move the delocalised electrons move with them and maintain the electrostatic attraction between them

Question 29

What is ionic bonding between?

Answer 29

Metal and non metal ions

Question 29

What is the shape and bond angle of H2O?

Answer 29

104.5 v shaped/non linear

Question 30

What molecules does Van Der Waals occur between?

Answer 30

Non polar

Question 32

What is the bond angle and shape of Ch4?

Answer 32

109.5 degrees tetrahedral

Question 33

How does Van Der Waals forces arise?

Answer 33

There is a higher electron density at one side creating an instantaneous dipole
The instantaneous dipole induces a dipole in a neighbouring molecule
The instantaneous dipole and induced dipole attract each other

Question 34

What is the definition of metallic bonding?

Answer 34

Strong electrostatic attraction between delocalised electrons and positive cations

Question 35

What molecules does hydrogen bonding occur between?

Answer 35

Polar hydrogen atom and F O N

Question 36

How does hydrogen bonding affects the properties of water?

Answer 36

Solid ice is less dense than water-hydrogen bonds hold water apart in open lattice structure giving it lower density
Relatively high MP BP-energy is required to break bonds and it takes more energy to break hydrogen bonds as it is the strongest intermolecular force

Question 36

Why do metallically bonded substances have high MP BP

Answer 36

Strong electrostatic attraction between delocalised electrons and positive ions requires a lot of energy to overcome

Question 37

Why do metallically bonded items conduct electricity?

Answer 37

delocalised electrons can move and carry charge