Bonding ( AS )

Question 1

What is ionic bonding?

Answer 1

Strong electrostatic force of attraction oppositely charged ions held in a lattice

Question 2

Give an example of ionically bonded substance

Answer 2

NaCl(sodium chloride-salt)

Question 3

Do ionically bonded substances have a high melting and boiling point?

Answer 3

High - it takes a lot of energy to break the strong electrostatic forces of attraction between opposite charged ions

Question 4

Can ionic compounds conduct electricity?

Answer 4

Yes, when molten or aqueous as the ions are free to move and carry charge(don’t when in solid state)

Question 5

What is simple molecular covalent bonding?

Answer 5

Strong covalent bonds between atoms, weak van der waals forces between molecule

Question 6

Are there any lone pair electrons in simple covalent bonding?

Answer 6

No-all involved in bonding

Question 7

Can simple molecular covalent molecules conduct electricity?

Answer 7

No-all electrons are used in bonding and aren’t free to move

Question 8

Do simple molecular substances have a high melting and boiling point?

Answer 8

Low-weak van der waals forces between molecules that don’t take much energy to overcome

Question 9

Describe macromolecular covalent bonding

Answer 9

Lattice of many atoms held together by strong covalent bonds

Question 10

Do substances with macromolecular covalent binds have high melting and boiling points?

Answer 10

High, as it takes a lot of energy to overcome many strong covalent bonds

Question 11

Do substances with macromolecular covalent bonds conduct electricity?

Answer 11

Most don’t, as all electrons are used in bonding

Question 12

What’s metallic bonding?

Answer 12

Lattice of positive metal ions strongly attracted to a sea of delocalised electrons

Question 13

Do metallic compounds have a high melting and boiling point?

Answer 13

High as strong forces of attraction between positive metal ions and negatively charged sea of delocalised electrons

Question 14

Do metallic compounds conduct electricity?

Answer 14

Yes, as delocalised electrons can move throughout the metal to carry charge

Question 15

How does the strength of metallic bonds change across the perodic table?

Answer 15

Increases—>higher melting and boiling point, higher charge on metal ions, more delocalised electrons per ion, stronger forces of attraction between them

Question 16

Define electronegativity

Answer 16

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

Question 17

What affects electronegativity?

Answer 17

Nuclear charge
Atomic radius
Electron shielding

Question 18

What is the most electronegative element?

Answer 18

Fluorine(4.0 on Paulings scale)
Largest nuclear charge for its electron shielding, small atomic radius

Question 19

How do you get a non-polar bond?

Answer 19

Both bonding elements have the same electronegativities

Question 20

When do you get a polar bond?

Answer 20

Bonding atoms have different electronegativities

Question 21

What is the strongest type of intermolecular force?

Answer 21

Hydrogen bonding

Question 22

What is the weakest type of intermolecular force?

Answer 22

Van der waal forces

Question 23

Describe van der waals forces of attraction

Answer 23

●Temporary dipoles are created by the random movement of electrons
●induces dipole in neighbouring molecule
●temporary induced dipole-dipole attraction aka van der waals forces

Question 24

Are van der waals forces greater in smaller or larger molecules?

Answer 24

Larger-more electrons

Question 25

Describe permanent dipole-dipole attraction

Answer 25

Some molecules with polar bonds have permanent dipoles—> forces of attraction between those dipoles and those neighbouring molecules

Question 26

What conditions are needed for hydrogen bonding to occur?

Answer 26

O-H,N-H, or F-H bond, lone pair of electrons on O,F,N because O,N,and F are highly electronegative, H nucleas is left exposed.
Strong force of attraction between H nucleas and lone pair of electrons on O,N,F

Question 27

Why is ice less dense than liquid water?

Answer 27

In liquid water, hydrogen bonds constantly break and reform as molecules move about.
In ice, the hydrogen bonds hold the molecules in fixed positions; this makes them slightly further apart than in liquid water

Question 28

What is dative/ coordinating covalent bond? When is it formed?

Answer 28

A type of covalent bond where both the electrons in the shared pair come from the same atom

Question 29

What does the shape of molecule depend on?

Answer 29

●Number of electrons in the valence shell of the central atom
●number of these electrons, which are bonded or lone pairs

Question 30

What does the electron pair repulsion theory state?

Answer 30

Electron pairs will take up positions as far away from each other as possible to minimise the repulsive forces between them

Question 31

Which experience the most repulsion?

Answer 31

LP-LP repulsion strongest
LP-BP repulsion middle
BP-BP repulsion weakest

Question 32

What is the shape, diagram, and bond angle in a shape with 2 bonded pairs and 0 lone pairs?

Answer 32

Linear
180°

Question 33

What is the shape, diagram, and bond angle in a shape with 3 bonding pairs and 0 lone pairs?

Answer 33

Trigonal planar
120°

Question 34

What is the shape, diagram, and bond angle in a shape with 4 bonding pairs and 0 lone pairs?

Answer 34

Tetrahedral
109.5°

Question 35

What is the shape, diagram, and bond angle in a shape with 5 bonded pairs and 0 lone pairs?

Answer 35

Trigonal Bipyramidal
90° and 120°

Question 36

What is the shape, diagram, and bond angle in a shape with 6 bonded pairs and 0 lone pairs?

Answer 36

Octahedral
90°