Unit 1: Section 3- Bonding

Question 1

Define ionic bonding

Answer 1

Ionic bonding is the electrostatic force of attraction between oppositely charged ions formed by electron transfer

Question 2

What type of ion does a metal form?

Answer 2

positive

Question 3

What type of ion does a non metal form?

Answer 3

negative

Question 4

What structure do ionic crystals have?

Answer 4

giant lattice of ions

Question 5

How does the size of the ions affect the properties of the bond?

Answer 5

ionic bonding is stronger and the melting points higher when the ions are smaller

Question 6

How can the charges affect the strength of the ionic bond?

Answer 6

if the charges are higher, the ionic bonds are stronger

Question 7

Explain why negative ions formed in group 5 to 7 are larger

Answer 7

the negative ion has more electrons than the corresponding atom but the same number of protons, so the pull of the nucleus is shared over more electrons, and the attraction per electron and the attraction per electron is less, making the ion bigger

Question 8

What happens to ionic radii size going down a group?

Answer 8

it increases, because there are more shells of electrons

Question 9

What is a covalent bond?

Answer 9

shared pair of electrons

Question 10

What is a dative covalent bond?

Answer 10

when the shared pair of electrons comes from only one of the bonding atoms

Question 11

What is metallic bonding?

Answer 11

metallic bonding is the electrostatic force of attraction between the positive metal atoms and delocalised electrons

Question 12

Name three things that effect the strength of a metallic bond

Answer 12

• number of protons (strength of nuclear attraction)
• number of delocalised electrons
• size of the ions

Question 13

What is the structure of ionic bonded molecules?

Answer 13

giant ionic lattice

Question 14

What is the structure of molecules that are covalently bonded?

Answer 14

simple molecular: (Van der Waals forces, permanent dipoles, hydrogen bonds)

macromolecular: giant molecular structures

Question 15

What is the structure of molecules that are metallically bonded?

Answer 15

giant molecular lattice

Question 16

What words do you use to describe simple molecular substances?

Answer 16

molecules
intermolecular forces

Question 17

State the solubility in water of ionic, molecular, macromolecular and metallic compounds

Answer 17

Generally good
generally poor
insoluble
insoluble

Question 18

State how conductive when solid ionic, molecular, macromolecular and metallic compounds are

Answer 18

poor
poor
poor
good

Question 19

State how conductive when molten ionic, molecular, macromolecular and metallic compounds are

Answer 19

good
poor
poor
good

Question 20

State the BP and MPs of ionic, molecular, macromolecular and metallic compounds

Answer 20

high
low
high
high

Question 21

Describe a linear molecule

Answer 21

2 bonding pairs
0 lone pairs
bond angle- 180

Question 22

Name three examples of linear molecules

Answer 22

CO2 CS2 HCN

Question 23

Describe a trigonal planar molecule

Answer 23

3 bonding pairs
0 lone pairs
bond angle- 120

Question 24

Name 3 examples of trigonal planar molecules

Answer 24

BF3
AlCl3
SO3

Question 25

Describe a tetrahedral molecule

Answer 25

4 bonding pairs 0 lone pairs bond angle- 109.5

Question 26

Name two examples of tetrahedral molecules

Answer 26

SiCl4, SO4 2-

Question 27

Describe a trigonal pyramidal molecule

Answer 27

3 bonding pairs 1 lone pair bond angle- 107

Question 28

Describe a bent molecule

Answer 28

2 bonding pairs 2 lone pairs bond angle- 104.5

Question 29

Describe a trigonal bipyramidal molecule

Answer 29

5 bonding pairs 0 lone pairs bond angle- 120 and 90

Question 30

Describe an octahedral molecule

Answer 30

6 bonding pairs 0 lone pairs bond angle- 90

Question 31

Explain which repels more: lone pairs or bonding pairs

Answer 31

lone pairs- by about 2.5 degrees more per lone pair

Question 32

Define electronegativity

Answer 32

the relative tendency of an atom in a covalent bond in a molecule to attract electrons in a covalent bond to itself

Question 33

How is electronegativity measured?

Answer 33

Pauling scale (1-4)

Question 34

What are the most electronegative elements?

Answer 34

fluorine, oxygen, nitrogen, chlorine

Question 35

Describe the trend in electronegativity along a period

Answer 35

increases as the number of protons increases and the atomic radius decreases because the electrons in the same shell are pulled in more

Question 36

Describe the trend in electronegativity down a group

Answer 36

it decreases down a group because the distance between the nucleus and the outer electrons increases and the shielding of inner shell electrons increases

Question 37

What type of bonding will a compound have if it contains elements of a similar electronegativity?

Answer 37

purely covalent

Question 38

What type of bonding will a compound have if it contains elements with a large electronegativity difference?

Answer 38

ionic

Question 39

When does a polar covalent bond form?

Answer 39

when the elements in the bond have different electronegativities (0.3-1.7)

Question 40

What is a polar covalent bond?

Answer 40

a bond where it has an unequal distribution of electrons in the bond and produces a charge separation (dipole ends)

Question 41

How do you identify a symmetrical molecule?

Answer 41

all bonds identical and no lone pairs of electrons

Question 42

Can a symmetrical molecule be polar?

Answer 42

no, even if the individual bonds within the molecule are polar

Question 43

Give an example of a symmetrical molecule

Answer 43

CO2

Question 44

What molecules do Van der Waals forces occur in?

Answer 44

everything except ionic substances

Question 45

What are Van der Waals also called?

Answer 45

transient, induced dipole- dipole interactions

Question 46

How do Van der Waals forces occur in molecules?

Answer 46

the electrons are moving constantly and randomly, so the electron density can fluctuate and parts of the molecule become more or less negative

Question 47

What is the main factor affecting the size of Van der Waals forces?

Answer 47

the more electrons there are in the molecule the higher the chance that temporary dipoles will form, so stronger Van der Waals forces

Question 48

How can you explain the increasing boiling points down group 7?

Answer 48

increasing numbers of electrons, bigger molecules, so increasing Van der Waals forces between molecules.

Question 49

What is the trend in boiling points down group 7?

Answer 49

increasing

Question 50

How can you explain why I2 is a solid and Cl2 is a gas?

Answer 50

Van der Waals forces

Question 51

How can increasing boiling points of alkanes be explained?

Answer 51

long, more electrons, stronger Van der Waals

Question 52

What does the permanent dipole-dipole force occur between?

Answer 52

polar molecules

Question 53

Which bonds are stronger, dipole-dipole or Van der Waals forces?

Answer 53

permanent dipole- dipole

Question 54

What type of molecules are polar molecules?

Answer 54

asymmetrical

Question 55

How do polar molecules form a bond?

Answer 55

the significant difference in electronegativity

Question 56

How does hydrogen bonding occur?

Answer 56

it occurs in compounds that have hydrogen atom attached to one of the three most electronegative atoms of nitrogen, oxygen and fluorine. which must also have an available lone pair of electrons

Question 57

What is the strongest type of intermolecular bonding?

Answer 57

hydrogen bonding

Question 58

Why is the boiling point of H2O so anonamously high?

Answer 58

the hydrogen bonding between the molecules

Question 59

What can form hydrogen bonds?

Answer 59

alcohols, carboxylic acids, proteins, amides