4 - Bonding

Question 1

Types of bonds?

Answer 1

Covalent, dative covalent & ionic

Question 2

Which bond forms between non-metals and metals?

Answer 2

Ionic

Question 3

What happens to electrons in an ionic bond

Answer 3

They are either gained or lost

Question 4

What happens to electrons in a covalent bond

Answer 4

They are shared between atoms

Question 5

What is a covalent bond?

Answer 5

A shared paired of electrons make a covalent bond

Question 6

How are covalent bonds formed?

Answer 6

Each atom in the bond shares one electron to form a bonding pair of electrons

Question 7

How are dative bonds formed?

Answer 7

One of the atoms in the bond provides both electrons of the bonding pair

Question 8

Examples of dative bonds

Answer 8

Ammonium, CO, nitric acid

Question 9

Single bonds are always _________

Answer 9

Sigma bonds

Question 10

Double bonds are made of ______ & ______

Answer 10

1 sigma and 1 pi bond

Question 11

In which orbitals do sigma bonds occur?

Answer 11

s, p and hybrid orbitals

Question 12

When do pi bonds form?

Answer 12

When two p orbitals overlap sideways

Question 13

Which is stronger, pi or sigma bonds?

Answer 13

Sigma bonds are stronger. Pi bonds are further from the nucleus

Question 14

Where is electron density in pi bonds?

Answer 14

Above and below internuclear axis

Question 15

What are allotropes?

Answer 15

Different forms of the same element (e.g. graphite and diamond)

Question 16

VSEPR Shape and angle: 2 bonding pairs

Answer 16

Linear, 180 (e.g. CO2)

Question 17

VSEPR Shape and angle: 3 bonding pairs

Answer 17

Trigonal planar, 120 (e.g. Boron hydride)

Question 18

VSEPR Shape and angle: 4 bonding pairs

Answer 18

Tetrahedral (3D), 109.5 (e.g. CH4)

Question 19

VSEPR Shape and angle: 5 bonding pairs

Answer 19

Trigonal bypyramidal (3D), one plane at 180, others at 90 (e.g. Phosphorus pentaflouride)

Question 20

VSEPR Shape and angle: 6 bonding pairs

Answer 20

Octahedral (3D), all planes at 90 to each other (e.g. SF6)

Question 21

What is the effect of lone pairs on bond shapes?

Answer 21

Lone pairs are closer to nucleus, so they repel the bonding pairs, increasing bond length and shortening bond angle

Question 22

What does resonance state?

Answer 22

Resonance states that when there are multiple ways to draw Lewis diagrams, all possibilities are correct. (bonds can change to opposite sides)

Question 23

What does ozone do in the atmosphere?

Answer 23

Blocks out UVB & UVC

Question 24

Shape and angle: 4 bonding pairs, 2 lone pairs

Answer 24

Square planar, 90 (e.g. Xenon tetraflouride)

Question 25

Shape and angle: 4 bonding pairs, 1 lone pair

Answer 25

See-saw, 90 & 120

Question 26

What causes ozone to break down?

Answer 26

CFCs and NO

Question 27

Formal charge for most stable atoms?

Answer 27

- Lowest possible | - Negative on electronegative atoms

Question 28

Types of hybridization

Answer 28

sp, sp2, sp3

Question 29

More the difference in electronegativity in a molecule, more the _______

Answer 29

Polarity

Question 30

Types of intermolecular forces with examples

Answer 30

- van der Waals forces (I2, iodine) - Permanent dipole-dipole forces (HCl) - Hydrogen bonds (water)

Question 31

Rank intermolecular forces from strongest to weakest

Answer 31

1) Hydrogen bonds 2) Permanent dipole-dipole forces 3) Weakest: van der Waals forces

Question 32

What causes the strong attraction in hydrogen bonds?

Answer 32

A vast difference in electronegativity between H and O, N or F

Question 33

What factors cause van der Waals forces to increase?

Answer 33

- Size of molecule increases | - Long, straight molecules have more van der Waals

Question 34

VSEPR Shape and angle: 2 bonding atoms, 1 lone pair

Answer 34

Bent (V-shaped),

Question 35

VSEPR Shape and angle: 1 bonding pair, 2 lone pairs

Answer 35

Linear, 180°

Question 36

VSEPR Shape and angle: 3 bonding atoms, 1 lone pair

Answer 36

Trigonal pyramidal,

Question 37

VSEPR Shape and angle: 2 bonding atoms, 2 lone pairs

Answer 37

Bent (V-shaped),

Question 38

VSEPR Shape and angle: 4 bonding atoms, 1 lone pair

Answer 38

See-saw, 90° & 120°

Question 39

VSEPR Shape and angle: 3 bonding atoms, 2 lone pairs

Answer 39

T-shaped, 90° & 120°

Question 40

VSEPR Shape and angle: 5 bonding atoms, 1 lone pair

Answer 40

Square pyramidal, 90° & 180°

Question 41

VSEPR Shape and angle: 4 bonding atoms, 2 lone pairs

Answer 41

Square planar, 90° & 180°