Ionic bond

Question 1

common ionic compounds in daily life

Answer 1

sodium chloride NaCl table salt
sodium bicarbonate NaHCO3 baking soda
sodium hydroxide NaOH lye drain cleaner
magnesium sulfate MgSO4 Epsom salt
sodium hypochlorite NaOCI bleach

Question 2

what is octet rule

Answer 2

Atoms of elements tend to combine in such a way that they have eight
electrons in their outermost/valence electron shell (two electrons for
period 1 elements), giving them the same electron arrangement as a
noble gas (octet structure).

Question 3

how do atoms obtain octet structure

Answer 3

They achieve this by either transferring electrons or sharing electrons

Question 4

how are cations formed

Answer 4

Metal atoms lose electrons to become
cations (positive ions).

Question 5

how are anions formed

Answer 5

Non-metal atoms gain electrons to become
anions (negative ions).

Question 6

what determines the number of electrons gained or lost

Answer 6

The number of electrons lost or gained is determined by the electron
configuration of the atom.

Question 7

what holds the positively and negatively
charged ions together

Answer 7

The positively and negatively
charged ions are held together in a
giant lattice

Question 8

what is a giant lattice

Answer 8

It is a regular 3D
arrangement with infinite ions - formed
by many strong ionic bonds.

Question 9

what is ionic bond

Answer 9

Strong electrostatic force of attractions
between oppositely charged ions.

Question 10

naming of ionic compounds

Answer 10

● When naming an ionic compound, cation should be
named first and followed by anion.
● No prefix needed to indicate the number of ions in
the compound.
● The charge of transition metal cations (several
possible charges) should be shown as a roman
numeral in a bracket.

Question 11

what does the physical properties of ionic compounds depend on

Answer 11

(a) type of structure,
(b) the type of constituent species, and
(c) the type (the strength) of attraction between constituent species

Question 12

Melting point and boiling point of ionic compounds

Answer 12

● Ionic compounds are solids under ambient conditions (25 °C and 1 atm).
● Strong electrostatic force of attractions between the oppositely charged ions
(ionic bond) in its lattice
● Large amount of heat energy is required to break the many strong bonds.

Question 13

what is volatility

Answer 13

Tendency of a substance to vaporize.

Question 14

volatility of ionic compounds

Answer 14

Ionic compounds are considered as being
non-volatile
○ large amount of energy needed to break
the strong ionic bonds in lattice

Question 15

hardness of ionic compounds

Answer 15

brittle and hard
If layers of ions slip against each other, ions with the same charge come up
against each other – like charges repel and break up the crystal

Question 16

electrical conductivity of ionic compounds

Answer 16

Movement of charges (e.g. electrons, ions) is needed to
conduct electricity.
● Solid ionic compounds do not conduct electricity -
ions are held firmly (fixed) in the lattice.
● Molten/ liquid ionic
compounds conduct
electricity.
● Mobile ions move to
conduct electricity
● Aqueous ionic
compounds (dissolved
in water) conduct
electricity.
● Mobile ions move to
conduct electricity.

Question 17

solubility rules (1)

Answer 17

All compounds with group 1 metal ions (e.g. Na+, K+) and ammonium ions (NH4+) are soluble.

Question 18

solubility rules (2)

Answer 18

All nitrates (NO3-) and hydrogencarbonates (HCO3-)
are soluble.

Question 19

solubility rules (3)

Answer 19

All carbonates (CO32-) and phosphates (PO43-) are
insoluble except those mentioned in (1), group 1 metal ions

Question 20

solubility rules (4)

Answer 20

All hydroxides (OH-) are insoluble except those
mentioned in (1), Ba(OH)2and Ca(OH)2
(sparingly soluble). It is an aqueous solution when it is
in the form of limewater. However, when it is formed during
reactions, it exists as an insoluble compound.

Question 21

solubility rules (5)

Answer 21

All sulphates (SO42-) are soluble except CaSO4 , BaSO4 ,
PbSO4 , Ag2SO4 .

Question 22

solubility rules (6)

Answer 22

All halides (Cl-, Br-, I-, general form: X-) are soluble
except PbX2 and AgX.

Question 22

what are ionic equations

Answer 22

Equations that only show the chemical species that have participated in the reaction (such as ions and molecules).

Question 23

what are spectator ions

Answer 23

Ions that are chemically unchanged for the entire process are called spectator ions - they can be removed from the equation.

Question 24

what is precipitation

Answer 24

When two aqueous ionic solutions are mixed together, if an insoluble ionic compound is produced, a precipitate will be formed. It is also known as the double replacement reaction

Question 25

what happens during the process of precipitation

Answer 25

During the process, the cations and the anions of the two solutions are exchanged.

Question 26

what is the precipitate

Answer 26

it is the insoluble ionic compound, it settles and falls to the bottom of the solution

Question 27

what is supernate

Answer 27

it is a solution which remains above a precipitate

Question 28

precipitation of silver chloride

Answer 28

When colourless silver nitrate solution is added to colourless sodium chloride solution, white precipitate of silver chloride is produced.
Overall equation:
AgNO3 (aq) + NaCl (aq) → AgCl(s) + NaNO3 (aq)
Ionic equation:
Ag+ (aq) + Cl-(aq) → AgCl(s)