Bonding (3.1.3-Phys.)

Question 1

What makes ionic bonds strong?

Answer 1

Electrostatic attraction between oppositely charges ions

Question 2

How are ionics formed?

Answer 2

Transfer of valence electrons

Question 3

The strength of the bond increases as….

Answer 3

Charge increases and size decreases

Question 4

How can ions conduct?

Answer 4

If they are liquid or aqueous since this is the only time where the ions can move

Question 5

Between NaCl and KCl, which has the higher melting point and why?

Answer 5

NaCl because it’s the smaller ion and so it has a shorter and stronger attraction.

Question 6

Between NaCl and MgCl2, which has the higher melting point and why?

Answer 6

MgCl2 because it has a higher ionic charge, a smaller ionic radius and more delocalised electrons

Question 7

When do ionic bonds form?

Answer 7

Between atoms with large differences in electronegativity

Question 8

How strong are simple molecular covalent bonds?

Answer 8

Very strong

Question 9

How are simple molecular covalent bonds formed?

Answer 9

Through a shared pair of electrons

Question 10

Short bond=

Answer 10

Strong bonds

Question 11

Why do simple molecular covalent bonds have low mpt/bpts?

Answer 11

They have weak intermolecular forces that require very little energy to overcome

Question 12

Why can’t simple covalents conduct?

Answer 12

Because they don’t contain any moving charged particles

Question 13

What occurs in dative covalent bonding?

Answer 13

One atom donates both electrons to share with the other atom(s)

Question 14

Name 3 forces between molecules with simple covalent bonds

Answer 14

• Van Der Waals forces
• Permanent dipole-dipole
• Hydrogen bonding

Question 15

Which is the weakest intermolecular force?

Answer 15

Van der Waals

• Exists btwn all simple covalent bonds
• Non polar bonds
• Temporary dipole of 1 molecule induces a dipole in another molecule
• Spherical forms have lower SA and fewer vdw, lower bpt

Question 16

Which is the second strongest intermolecular force?

Answer 16

Permanent dipole-dipole

• Slight charges due to difference in electronegativity
• polar molecules
• non-symmetrical

Question 17

What is the strongest intermolecular force?

Answer 17

Hydrogen bonding

• Bonded to N, O and F only
• Short strong hydrogen bonds

Question 18

Why does S8 have a low mpt?

Answer 18

Very little energy required to break weak van der Waals forces

Question 19

Which has a higher mpt S8 or P4?

Answer 19

S8 because its bigger, so it will have more van der Waals forces between molecules.

Question 20

Why is ice less dense than water?

Answer 20

As water cools, there is a higher % of H bonds and the lattice structure formed. H bonds spread out pushing mol. away.

Question 21

What makes metallic bonds strong?

Answer 21

Forces of electrostatic attraction bwn delocalisd electrons and +ve metal ions.

Question 22

Higher strength =

Answer 22

Higher charge and smaller size

Question 23

Why can metals conduct electricity?

Answer 23

They can carry charge through delocalised electrons that can move.

Question 24

High charge density =

Answer 24

Stronger ions

Question 25

Define electronegativity

Answer 25

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

Question 26

What atoms have the highest and lowest electronegativity?

Answer 26

Highest= F
Lowest= Francium

Question 27

What leads to polar bonds?

Answer 27

Covalent bonds existing btwn atoms with differences in electronegativity