Bonding Flashcards
What is ionic bonding
transfer of electrons from a metallic element to a non-metallic element to form a full outer shell
electrostatic attraction formed between the oppositely charged ions
Cations and anions
Forming cations by the removal of electrons from metals
Forming anions by the addition of electrons to nonmetals
what are ionic compounds
Cations and anions are oppositely charged and therefore attracted to each other
Electrostatic attractions are formed between the oppositely charged ions to form ionic compounds
melting points in ionic
high melting points
attraction is very strong and requires a lot of energy to overcome
why are ionic lattice neutral
Ions in a lattice are arranged in a regular repeating pattern so that positive charges cancel out negative charges
when does ionic radius increase/decrease
Ionic radii increase with increasing negative charge
Ionic radii decrease with increasing positive charge
how does the strength of ionic bonding depend on charge
ionic charge. Bigger charges exert greater attractive forces between each other so the greater the charge on the ions involved, the stronger an ionic bond will be.
how does the strength of ionic bonding depend on ionic radius
he smaller the ions, the more closely they can be packed together in the ionic lattice. The shorter the distance between oppositely charged ions, the stronger the electrostatic forces between them and hence the stronger the ionic bond.
why does ionic radius increase a group
This is because as we go down a group, the number of outer electron shells increases.
why does ionic radius decrease along a period
Nuclear charge increases as more protons. Therefore, electrons are pulled in more strongly.
what are isoelectronic ions
the same electronic configuration but different numbers of protons, therefore will have a different ionic radius
how does the radius of isoelectronic ions work
As the number of protons in the nucleus of the ion increases, the electrons get pulled in more closely to the nucleus
The radii of the isoelectronic ions therefore fall across this series of ions
when can ionic compounds conduct electricity
conduct electricity when molten or dissolved because only then are the ions of the compound able to move and carry charge. Ionic compounds are unable to conduct electricity when solid because the ions are fixed in place and unable to carry charge.
why are ionic compounds soluble in water
ionic compounds and water molecules are partially charged molecules (polar). This means the partial charges of water break apart the ionic lattice, pulling oppositely charged ions apart and the ionic compound to dissolve
what are ionic compounds arranged in
giant ionic lattices.
what does it mean if ionic compounds are solids
there isn’t enough energy to overcome the strong electrostatic forces of attraction between the oppositely charged ions that make up the lattice
Therefore, high temperatures are required to make an ionic compound melt or boil
what does the solubility of ionic compounds depend on
Breaking down the ionic lattice
The polar molecules attracting and surrounding the ions
what is the evidence for existence of ions
electrolysis is a clear piece of evidence for the existence of ions
Positive ions in solution are attracted to the negative electrode
Negative ions in solution are attracted to the positive electrode
CuCrO4
Cu2+ ions (blue)
CrO42- ions (yellow)
blue colour appears around the negative electrode, and a yellow colour appears around the positive electrode
what is a covalent bond
electrostatic attraction between nuclei of two non-metal atoms and the bonding electrons
What us dative covalent bonding
Some molecules have a lone pair of electrons that can be donated to form a bond with an electron-deficient atom
what is bond energy
energy required to break one mole of a particular covalent bond in the gaseous states
what is bond length
internuclear distance of two covalently bonded atoms
when does bond length decrease
The greater the forces of attraction between electrons and nuclei, the more the atoms are pulled closer to each other
This decreases the bond length of a molecule and increases the strength of the covalent bond
Triple bonds are the shortest and strongest covalent bonds due to the large electron density between the nuclei of the two atoms
This increase the forces of attraction between the electrons and nuclei of the atoms
As a result of this, the atoms are pulled closer together causing a shorter bond length
The increased forces of attraction also means that the covalent bond is stronger
What are the bonding pair, lone pair and bond angle of linear
bonding - 2
lone - 0
bonding angle - 180
What are the bonding pair, lone pair and bond angle of v-shaped
bonding - 2
lone - 2
bonding angle - 104.5
What are the bonding pair, lone pair and bond angle of trigonal planar
bonding - 3
lone pair - 0
bonding angle - 120
What are the bonding pair, lone pair and bond angle of triangular pyramid
bonding - 3
lone pair - 1
bonding angle - 107
What are the bonding pair, lone pair and bond angle of tetrahedral
bonding - 4
lone pair - 0
angle - 109.5
What are the bonding pair, lone pair and bond angle of trigonal bypyramidal
bonding - 5
lond - 0
angle - 90 and 120
What are the bonding pair, lone pair and bond angle of octahedral
bonding - 6
lone - 0
angle - 90
describe metallic bonding
lattice of positive ions / regular arrangement of positive ions
(1)
(in sea of) delocalised electrons
(1)
strong forces of attraction between ions and delocalised electrons (so high melting temperature)
(1)
so lots of (heat) energy needed to break attraction between ions and delocalised electrons / metallic bonds
state conditions when magnesium bromide conducts electricity
molten and dissolved in water
predict two physical properties of a metal
high melting/ boiling temperature
strong (electrostatic) attraction between metal ions and delocalised electrons
- (good) electrical conductivity/ thermal conductivity
- mobile delocalised electrons (1)
- malleability/ ductility
*the layers of ions/ atoms can easily slide over each other
what is a covalent bond
(strong electrostatic) attraction
(1)
between two nuclei and the share /bonding pair of electrons
what does giant structure suggest
therefore contains many strong covalent bonds
why does co2 have polar bonds but its not a polar molecule
carbon dioxide is a symmetrical/linear molecule and so the dipole moments/vectors cancel
why is H20 polar molecule
oxygen is more electronegative than hydrogen
(M2) which results in a polar bond with oxygen delta negative so hydrogen delta positive
why do dipole moments of water no cancel
lone pairs of electrons of oxygen mean that the dipole moments vectors do not cancel
what things do you need to make reference to when talking about difference in boiling temperatures
London forces
which has more electrons
where dipole dipole is stronger
electronegativity
ALL TYPES OF DIFFERENT BONDS
how is london forces formed
uneven distribution of electrons results in formation of instantaneous dipole in first molecule which induces second dipole on another molecule
why does hydrogen bonding cause ice to be less dense than liquid water
as hydrogen bonds are longer than covalent bonds
more open / more space between molecules (making it less dense)
(1)
* due to (3 Dimensional) lattice / ring structure in ice (1)
three things
