3.1.3. Bonding

Question 1

What type of bonding exists between metals and non-metals?

Answer 1

Ionic bonding

Question 2

What happens to electrons in ionic bonding?

Answer 2

They are transferred from metal to non-metal

Question 3

Define ionic bonding

Answer 3

The electrostatic attraction between oppositely charged ions

Question 4

Describe the structure of ionic compounds

Answer 4

Giant ionic lattice of positive and negative ions held together by electrostatic forces

Question 5

Explain the melting point of ionic compounds

Answer 5

High melting point because strong electrostatic forces within ionic lattice

Question 6

Explain the electrical conductivity of ionic compounds

Answer 6

Conduct when molten or dissolved because ions can move but do not conduct as a solid because ions held in fixed position in lattice

Question 7

What happens to electrons in covalent bonding?

Answer 7

Electrons are shared between non-metal atoms

Question 8

Define covalent bonding

Answer 8

The electrostatic attraction between the positively charged nucleus and the negative bonding pairs of electrons

Question 9

What is the difference between a single and double covalent bond?

Answer 9

Single is 2 shared electrons in bond, double is 4 shared electrons

Question 10

Describe the bonding in diamond

Answer 10

Each carbon is bonded to 4 other carbons in a tetrahedral shape

Question 11

Describe the structure of graphite

Answer 11

Layers of carbon atoms arranged in hexagonal pattern with weak bonds and delocalised electrons between layers

Question 12

Explain why graphite conducts electricity

Answer 12

Delocalised electrons are free to move and carry charge

Question 13

Explain the hardness of diamond

Answer 13

Atoms are held in fixed positions

Question 14

What is a co-ordinate (dative) bond?

Answer 14

Where one atom contributes both electrons in a covalent bond

Question 15

Define metallic bonding

Answer 15

The electrostatic attraction between positively charged metal ions and the negatively charged sea of delocalised electrons

Question 16

Describe the structure of metals

Answer 16

Giant metallic lattice of positive metal ions surrounded by delocalised electrons

Question 17

How does the size of the ion affect melting point?

Answer 17

Increases with decreasing size

Question 18

How does the charge of the ion affect melting point?

Answer 18

Increased with increasing charge

Question 19

Explain why metals conduct electricity

Answer 19

Delocalised electrons are free to move and carry charge

Question 20

Explain why metals have high melting points

Answer 20

The dleocalised electrons are strongly attracted to the positive metal ions (strong metallic bonds) which requires a lot of energy to overcome

Question 21

What is electron pair repulsion theory?

Answer 21

Electron pairs repel each other as far apart as possible.

Question 22

Which has the greater repulsion effect - lone pair of electrons or a covalent bond?

Answer 22

Lone pair

Question 23

What is the bond angle in a linear molecule?

Answer 23

180

Question 24

What is the bond angle in a trigonal planar molecule?

Answer 24

120

Question 25

What is the bond angle in a tetrahedral molecule ?

Answer 25

109

Question 26

What is the bond angle in a trigonal bipyramidal molecule?

Answer 26

120 and 90

Question 27

What is the bond angle in an octahedral molecule?

Answer 27

90

Question 28

What shape molecule has 6 bonding electron pairs, eg. SF6?

Answer 28

Octahedral

Question 29

What shape molecule has 5 bonding pairs eg. PCl5?

Answer 29

Trigonal bipyramidal

Question 30

What shape molecule has 4 bonding pairs eg. NH4+?

Answer 30

Tetrahedral

Question 31

What shape molecule has 3 bonding pairs eg. BF3?

Answer 31

Planar

Question 32

What shape molecule has 2 bonding pairs eg. BeF2?

Answer 32

Linear

Question 33

How do lone pairs affect bond angles?

Answer 33

Reduce bonding pair bond angles (by approx 2 degrees) as they repel more than bonding pairs

Question 34

What is the shape and bond angle in water? Why?

Answer 34

Bent, 104.5 degree, 4 pairs of electrons including 2 lone pairs

Question 35

Where in the periodic table are the most electronegative elements?

Answer 35

Top right (not including noble gases)

Question 36

Which is the most electronegative element?

Answer 36

Fluorine

Question 37

What causes bond polarity?

Answer 37

Differences in electronegativity between two atoms bonded together

Question 38

What causes molecule to be polar (2 requirements)?

Answer 38

Significant differences in electronegativity in atoms in the molecule, and asymmetrical shape

Question 39

Define electronegativity

Answer 39

The ability of an atom to attract electron density (the electron pair) in a covalent bond

Question 40

Name the 3 types of intermolecular force in order from weakest to strongest

Answer 40

Van der Waals, dipole-dipole and hydrogen bonding

Question 41

Explain how Van der Waals forces arise

Answer 41

Temporary dipoles because of movement of electrons which induce temporary dipoles in neighbouring molecules

Question 42

Explain how dipole dipole forces arise

Answer 42

Partial positive charge attracting partial negative charge

Question 43

Explain why generally boiling point increases with increasing chain length

Answer 43

More Van der Waals forces

Question 44

Describe the structure of iodine

Answer 44

Molecular lattice of I2 molecules held toegher by Van der Waals forces

Question 45

What 3 elements could be bonded to hydrogen to give hydrogen bonding?

Answer 45

Oxygen, nitrogen or fluorine

Question 46

What is a hydrogen bond?

Answer 46

An electrostatic force of attraction between an N, O or F atom and a hydrogen atom that is bonded to another N, O or F atom

Question 47

How does hydrogen bonding affect boiling point?

Answer 47

Increases boiling point

Question 48

Describe the structure of ice

Answer 48

Regular lattice strucutre of water molecules held tgether by hydrogen bonding. Less dense than water