2.1- ionic model

Question 1

cations

Answer 1

metal atoms lose electrons they form positive ions= cations

Question 2

anions

Answer 2

when non-metal atoms gain electrons they form negative ions called anions

Question 3

why do atoms bond together

Answer 3

to achieve a decrease in their potential energy, this lower energetic state is more stable

Question 4

how is this “lower energetic state” achieved

Answer 4

by atims attaining a full electron shell

Question 5

what are the 3 types of electronic interaction resulting in 3 major types of bonding and what decides which type of bonding is used

Answer 5

which type of bonding occuring depending o the electronegativity of the atoms interacting with each other
ionic= low electronegativtity atoms (metals) interacting with high electronegativity atoms (non-metals)
covalent= both atoms have middle to high electroneagtivity (both non-metals)
metallic= bot atoms have low electronegativity (both metals)

Question 6

what is used to define if bond is ionic or covalent

Answer 6

compare electronegativity difference between two atoms
greater than 1.7 units=ionic
less than 1.7 units=covalent

Question 7

whats isoelectronic

Answer 7

when the atoms in an ionic bonding achieve the same electronic configuration as a noble gas

Question 8

ionic bonding

Answer 8

electrostatic attractions between opositely charged ions

Question 9

when ions have been formed what happens in an ionic bonding

Answer 9

when ions have been formed the electrostatic force of attraction between oppositley charged ions causes them to pack together into a 3dimensinal giant ionic lattice with every cation surrounded by anions and vis versa

Question 10

why are the cations smaller than the metal atoms

Answer 10

because the cation has formed through the loss of the outermost energy level (valence shell) because the anion has formed by the gain of electrons they are bigger than the neutral atom due to increase electron electron repulsion adn expansion of the outer energy level. In general the cation is smaller than anion

Question 11

ammonium cation

Answer 11

NH4+

Question 12

sulphate anion

Answer 12

SO4,2-

Question 13

carbonate anion

Answer 13

CO3,2-

Question 14

nitrate anion

Answer 14

NO3-

Question 15

phosphate anion

Answer 15

PO4, 3-

Question 16

hydroxide anion

Answer 16

0H-

Question 17

Hydrogencarbonate

Answer 17

HCO3-

Question 18

do ionic susbtances conduct electricity

Answer 18

yes when molten or in solution, ions are free to move arund and can pass to the electrodes dipped in solution to become oxidised or reduced

Question 19

do ionic susbtances have high melting or boiing point

Answer 19

yes, a large numer of ionic bonds must be broken to allow the ions to move around (a molten liquid_ or break free from the attractive forces completely (ionic gas)

Question 20

are ionic substances hard and brittle

Answer 20

yes, does not bend, once sufficient force is applied the structure gives away completely and the material snaps

Question 21

are ionic susbtances soluble

Answer 21

more soluble in polar solvents that have an uneven charge distribution(such as water) thhan non-polar solvents (such as hexane) the ions become surrounded by the polar solvent molecules and are dissolve

Question 22

how is the strength of an ionic lattice measured

Answer 22

by its lattice enthalpy which is the energy recquired to break up a mole of an ionic lattice into gaseous ions under standard conditions

Question 23

lattice enthalpy

Answer 23

enthalpy change when one mole of solid ionic compound is seperated into its gaseous ions.

Question 24

the magnitude of the lattice enthalpy is a measure of

Answer 24

the stability of the ionic lattice 2 factors affect the stability:
size of the ions= smaller ions more closely the ions can pack together and attract each other
charge on the ion= the more charged is the ion the stronger is the electrostatic force of attraction between them

Question 25

anions ending in -ate are

Answer 25

covalent groups of oxygen and another non-metal
where the metal name (cation group) comes first and ending f anion name changes to -ide

Question 26

describe lattice enthalpy relationship with charge on cation adn anion
and with sum of ionic radii

Answer 26

directly porpotional to charge on cation adn cahrge n anion

inversely porportional to ionic radii

Question 27

equation for lattice enthalpy

Answer 27

charge on cation x charge on anion/ sum of ionic radii