Types of bonding

Question 1

Define sigma bonds

Answer 1

Bonds formed by linear overlapping (s-s bond, s-p bonds or p-p bonds)

Question 2

Define Pi bonds

Answer 2

Bonds formed by parallel overlapping (only p-p bonds)

Question 3

Give a definition for bond length

Answer 3

The distance between 2 nuclei

Question 4

As the bond length increases, what happens to bond strength?

Answer 4

Bond strength decreases

Question 5

As bond length increases, what happens to atomic size?

Answer 5

Atomic size increases

Question 6

As bond length increases, what happens to bond order?

Answer 6

bond order decreases

Question 7

Define electrongativity

Answer 7

The ability of an atm to attract the shared pair towards itself, giving it a partially negative charge.

Question 8

Which atom has the highest electronegativity

Answer 8

Fluorine

Question 9

What happens to electronegativity down a group?

Answer 9

Decreases

Question 10

What happens to electrongetavity across a period?

Answer 10

Increases

Question 11

By electronegativity difference what is the polarity of a molecule between 0 - 0.6

Answer 11

Non-polar

Question 12

By electronegativity difference what is the polarity of a molecule between 0.6 - 1.6

Answer 12

Polar

Question 13

By electronegativity difference what is the polarity of a molecule between 1.6 - + …

Answer 13

Ionic

Question 14

If a molecule is polar/non-polar can it be ionic? (Yes/No)

Answer 14

No, all polar/non-polar molecules are covalently bonded.

Question 15

Apart from electronegativity difference, how else can we see if a molecule is polar/non-polar? (4)

Answer 15

Non polar:
> All the atoms surrounding the central atom are the same. E.g. NH3 (Homoatomic)

> Hydrocarbon

Polar:

> Diff atoms around central atom

> Lone pairs found

Question 16

In intermolecular forces, what do 2 polar molecules form?

Answer 16

a dipole-dipole force of attraction

Question 17

In intermolecular foces, what do 2 non-polar molcules form?

Answer 17

Instantanious dipole-induced dipole force of attraction (London dispersion forces)

Question 18

How do london dispersion forces come about?

Answer 18

When 2 non-polar molecules approach each other, their electrons repel allowing for a partially negative and positive molceule to form which attracts.

Question 19

In intermolecular forces, which atoms does hydrogen need to approach for it to form hydrogen bonding?

Answer 19

Nitrogen, oxygen or fluorine

Question 20

Why is hydrogen bonding the strongest form of intermolecular forces?

Answer 20

Because the atoms it forms intermolecular forces have lone pairs and it is more polar.

Question 21

Rank the intermolecular forces from strongest to weakest:
dipole-dipole
hydrogen bonding
london dispersion

Answer 21

1) Hydrogen bonding
2) Dipole-Dipole
3) London Dispersion

Question 22

Why can some london dispersion forces be stronger than others?

Answer 22

Stronger london dispersion forces have a larger surface area

Question 23

What differentiates coordinate bonding (covalent) from hydrogen bonding (intermolecular force) (2)

Answer 23

1) Hydrogen bonding is much weaker than the covalent bonding of coordinate bonding

2) Covalent bonding includes sharing of electrons, while hydrogen bonding is purely from partial negative and positive attraction

Question 24

Rank these in order of strongest to weakest:
Ionic, intermolecular forces, covalent, metallic

Answer 24

1) Ionic
2) Covalent
3) Metallic
4) Intermolecular

Question 25

What type of bonding occurs in a single bond?

Answer 25

sigma

Question 26

What type of bonding occurs in a double bond?

Answer 26

sigma & pi

Question 27

What type of bonding occurs in a triple bond?

Answer 27

1 sigma & 2 pi