2.2.2 Bonding and Structure

Question 1

What is ionic bonding present in?

Answer 1

in compounds usually consisting of a metal and a non metal

Question 2

Definition of ionic bonding

Answer 2

its the electrostatic attraction between positive and negative ions

Question 3

dot and cross diagram for of Na2O (ionic bonding)

Answer 3

draw it

Question 4

how is a giant ionic lattice formed?

Answer 4

Each ion is surrounded by oppositely charged ions. These ions attract each other from all directions, forming a three dimensional giant ionic lattice.

Question 5

3 properties of ionic compounds

Answer 5

> high melting and boiling points
cannot conduct electricity
is soluble in polar substances

Question 6

why do ionic compounds have high melting and boiling points?

Answer 6

large amount of energy is needed to break the strong electrostatic bonds that hold the oppositely charged ions together in the solid lattice.

Question 7

how does the charge affect the melting point?

Answer 7

the greater the charge, the stronger the electrostatic forces between the ions therefore more energy is required to break up the ionic lattice

Question 8

Why do solid ionic lattice not conduct electricity?

Answer 8

because the ions are held in fixed positions and no ions can move

Question 9

describe an ionic lattice as been soluble

Answer 9

it can dissolve in polar substances such as water as polar substances have polar bonds.

Question 10

What are polar bonds?

Answer 10

they occur between atoms that do not share electrons equally, and it results in the atom having very small charge on them

Question 11

How does an ionic lattice break down in water

Answer 11

> Polar water molecules break down an ionic lattice by surrounding each ion to form a solution.
The slight charges within the polar substances are able to attract the charged ions in the giant ionic lattice.
This means the lattice is disrupted and ions are pulled out of it

Question 12

What is covalent bonding?

Answer 12

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

Question 13

what is one double bond

Answer 13

when two pairs of electrons are shared between two atoms

Question 14

what is one triple bond?

Answer 14

when three pairs of electrons are shared between two atoms

Question 15

what is 2 double bond?

Answer 15

when 2 pairs of electrons are spread between three atoms

Question 16

what is average bond enthalpy

Answer 16

it allow you to measure the strength of covalent bond

Question 17

The larger the value of the average bond enthalpy…

Answer 17

… the stronger the covalent bond

Question 18

What is a dative covalent bond

Answer 18

its when one of the atom supplies both the shared electrons to the covalent bond

Question 19

what are the types of covalent structures

Answer 19

> A simple molecular lattice

> A giant molecular lattice

Question 20

what are simple molecular structures made up from?

Answer 20

from small, simple molecules

Question 21

What are atoms and molecules held together by in simple molecular structures

Answer 21

> Atoms are held together by strong covalent bonds

> Different molecules are held together by weak intermolecular forces (such as van der waals)

Question 22

properties of simple molecular structures

Answer 22

> Low melting and boiling point
Non conductor of electricity
Soluble

Question 23

why does simple molecular structures has a low melting and boiling point

Answer 23

because the intermolecular forces are weak so small amount of energy is needed to break them

Question 24

why is a simple molecular structures a non conductor of electricity

Answer 24

because there are no charged particles free to move

Question 25

why is a simple molecular structures soluble

Answer 25

its soluble in non polar solvents, such as hexane as the weak van der waals forces are able to form between covalent molecules which helps the molecular to break down and dissolve

Question 26

properties of giant covalent structures

Answer 26

> High melting and boiling point
non conductor of electricity
insoluble in both polar and non polar

Question 27

why does a giant covalent structures have a high melting and boiling point

Answer 27

as high temperature is needed to break the strong covalent bonds within the lattice

Question 28

why is a giant covalent structures a non conductor of electricity

Answer 28

because there are no free particles

Question 29

why is a giant covalent structures insoluble

Answer 29

because the covalent bonds in the lattice are too strong to be broken