Bonding

Question 1

What creates the ionic lattice?

Answer 1

The ions attracting oppositely charged ions in all directions

Question 2

What state are most ionic compounds at room temperature?

Answer 2

-Solid

Question 3

Why do ionic compounds have high melting points?

Answer 3

-strong electrostatic forces of attraction between ions

Question 4

Why do ionic lattices with greater charges have greater melting points?

Answer 4

There are stronger forces of attraction between ions

Question 5

What do most ionic compounds dissolve in?

Answer 5

Polar solvents

Question 6

How does an ionic compound dissolve in water?

Answer 6

The polar water molecules break down the lattice by isolating the ions

Question 7

Why are lattices with grater ionic charge generally less soluble?

Answer 7

There is a stronger electrostatic attraction between particles

Question 8

What is the formula for an ammonium ion?

Answer 8

NH4+

Question 9

What is the formula for a nitrate ion?

Answer 9

NO3-

Question 10

What is the formulae for a sulfate ion?

Answer 10

SO42-

Question 11

What is the formula for a phosphate ion?

Answer 11

PO43-

Question 12

What is covalent bonding?

Answer 12

The strong electrostatic attraction between a shared pair of electrons and the nuclei of the bonded atoms

Question 13

How does a covalent bond take place?

Answer 13

The overlap of atomic orbitals (one in each orbital to form a pair)

Question 14

Why are covalent bonds “localised”?

Answer 14

The bond is purely between atoms

Question 15

How many single covalent bonds does boron tend to make?

Answer 15

3

Question 16

Despite it’s outer electrons being n=3, how many covalent bonds can phosphorus make? What is this called?

Answer 16

5 - expansion of the octet

Question 17

What is another word for a dative bond?

Answer 17

A coordinate bond

Question 18

What is a dative bond?

Answer 18

When the shared pair of electrons has been supplied by one of the bonding atoms only

Question 19

What is a dative bond shown by?

Answer 19

——>

Question 20

What is average bond enthalpy a measurement of?

Answer 20

Covalent bond strength

Question 21

What does a greater bond enthalpy value indicate?

Answer 21

A stronger covalent bond

Question 22

Why does H3O have a 1+ charge?

Answer 22

A pair of electrons is provided by the oxygen atom as it pairs with a H+ ion

Question 23

How are ionic compounds formed?

Answer 23

When 2 oppositely charged ions attract and are held together by electrostatic forces

Question 24

What are 3 properties of ionic compounds?

Answer 24

1) High MP and BPs
2) Can’t conduct electricity when solid
3) When molten or aqueous can conduct electricity

Question 25

Why can ionic compounds conduct electricity when molten or aqueous?

Answer 25

The ions are mobile and can move to opposite terminals and carry charge

Question 26

How are the ions in a lattice isolated by the polar water molecules?

Answer 26

The ions are attracted to slight charges on the polar molecule

Question 27

Why can a sodium ion form more than one ionic bond even though it only has one outer electron?

Answer 27

Each ions is attracted to all nearby ions

Question 28

Why do lone pairs repel more strongly than bonded pairs?

Answer 28

They are held closer to the central atom

Question 29

What is the electron pair repulsion theory used for?

Answer 29

To predict and explain the shapes of molecules

Question 30

Why do larger ions have a weaker attraction to the oppositely charged ion?

Answer 30

They have a greater ionic radius, so attractive forces have to act over a greater distance.

Question 31

Why are ionic substances often brittle?

Answer 31

The layers of alternating chargers are distorted when force is applied, so like charges repel, breaking apart the lattice into fragments.

Question 32

In a covalent bond dot and cross diagram, are the electrons on the lines or inbetween?

Answer 32

Doesn’t matter but should do it in between

Question 33

Why are shorter covalent bonds stronger ?

Answer 33

Atoms are held closer together so the forces of attraction are greater and require more energy to overcome

Question 34

Are double and triple bonds shorter than single covalent bonds?

Answer 34

Yes so they are stronger

Question 35

Why is a dative bond treated as a standard covalent bond once it has formed?

Answer 35

It reacts exactly the same way and has the same properties regarding length and strength