2:Bonding & Structure

Question 1

What is an ionic bond?

Answer 1

Strong electrostatic attraction between oppositely charges ions.

Question 2

How does ionic radius & charge effect the strength of an ionic bond?

Answer 2

The greater the charge of the ion the stronger the bond.

The greater the ionic radius the weaker the bond.

Question 3

What are cations?

Answer 3

Positively charged ions. Lost electrons.

Question 4

What are anions?

Answer 4

Negatively charged ions. Gained electrons.

Question 5

What is a covalent bond?

Answer 5

Strong electrostatic attraction between two nuclei & the shared pair of electrons between them.

Question 6

What are the properties of ionic compounds?

Answer 6

High melting point due to strong electrostatic attraction between ions.
The can conduct electricity in solution a melted due to the ions being able to move.
Soluble in water.

Question 7

What is a dative bond?

Answer 7

When the two electrons derive from the same atom when forming the covalent bond.

Question 8

Give an example of molecules containing dative bonds?

Answer 8

Al2Cl6 and ammonium ion.

Question 9

How does bond length effect bond strength?

Answer 9

The longer the bond the weaker the bond due to the shared pair of electrons being further away from the nucleus.

Question 10

How is the shape of molecules determined?

Answer 10

By the repulsion between the electron pairs that surround a central atom, and any lone pairs that may be present.

Question 11

Give the number or bonded & lone pairs, bond angle & an example of a Linear molecule?

Answer 11

2 bonded no lone.
180
BeCl2.

Question 12

Give the number or bonded & lone pairs, bond angle & an example of a V-shaped molecule?

Answer 12

2 bonded, 2 lone.
104.5
H2O.

Question 13

Give the number or bonded & lone pairs, bond angle & an example of a trigonal planar molecule?

Answer 13

3 bonded, no lone.
120.
BF3.

Question 14

Give the number or bonded & lone pairs, bond angle & an example of a triangular pyramid molecule?

Answer 14

3 bonded, 1 lone.
107.
NF3.

Question 15

Give the number or bonded & lone pairs, bond angle & an example of a tetrahedral molecule?

Answer 15

4 bonded, no lone.
109.5.
CH4.

Question 16

Give the number or bonded & lone pairs, bond angle & an example of a trigonal bipyramid molecule?

Answer 16

5 bonded, no lone.
180 & 120
PCl5.

Question 17

Give the number or bonded & lone pairs, bond angle & an example of an octahedral molecule?

Answer 17

6 bonded, no lone.
90
SF6.

Question 18

What is electronegativity?

Answer 18

The power of an atom to attract bonded electrons in a covalent bond.

Question 19

What is the trend in electronegativity along a period?

Answer 19

It increases along a period due to the increase in nuclear charge.

Question 20

What is the trend in electronegativity down a group?

Answer 20

It decreases down a group as shielding increases.

Question 21

What does polarity mean?

Answer 21

When the electronegativities in a bond are different.

Question 22

What are London forces?

Answer 22

Occur due to random movement of electrons, causing temporary dipoles between molecules.
More electrons= stronger London forces.

Question 23

What are permanent dipole- dipole attractions?

Answer 23

Occurs between polar molecules.

More polar the molecule= stronger attraction.

Question 24

What are hydrogen bonds?

Answer 24

Only occurs between Hydrogen & Florine, oxygen or nitrogen. Strongest intermolecular force.

Question 25

What are the main properties of water?

Answer 25

High melting & Boiling point.
Ice is less dense than water.
Both due to very strong hydrogen bonds.

Question 26

What is the trend in boiling point in alkanes with increasing chain length?

Answer 26

As the chains get longer boiling point increases, due to more London forces.

Question 27

Why do alcohols have a lower boiling point than alkanes?

Answer 27

Alcohols can hydrogen bond, alkanes don’t.

Question 28

What is a metallic bond?

Answer 28

Strong electrostatic attraction between metal ions and their delocalised electrons.

Question 29

How does branching effect boiling points in alkanes?

Answer 29

Branched molecules have lowed boiling points due to less London forces between molecules.

Question 30

What is the boiling temp trend in hydrogen halides?

Answer 30

HF>HI>HBr>HCl

HF has hydrogen bonds. The rest is only London forces and weak dipole-dipole.

Question 31

Why is water a bad solvent was organic molecules such as alkanes & halogenoalkanes?

Answer 31

They cannot form hydrogen bonds with the water so they become insoluble.

Question 32

Why can alcohols dissolve in water?

Answer 32

They can form hydrogen bonds with the water molecules.

Question 33

Where are giant lattices present?

Answer 33

Ionic solids.
Covalently bonded solids e.g. diamond, graphite & silicon(IV) oxide.
Solid metals.

Question 34

What are the Properties of metallic bonds?

Answer 34

Good conductors due to the sea of delocalised electrons.
They are malleable due to the layers of positive ions can slide over each other.
Very high melting points.

Question 35

What is the structure of Diamond?

Answer 35

Carbon atoms bonded to four other carbon atoms. Giant covalent lattice.

Question 36

What is the structure of graphite?

Answer 36

Sheets of carbon atoms. They have free electrons that can move between layers, therefore it can conduct electricity.

Question 37

What is graphene?

Answer 37

2D sheets of graphite that are one atom thick. Sheets are formed of hexagonal carbon rings.