chap 3 Flashcards
(20 cards)
what are ionic compounds behaviours
- they conduct electricity when they’re molten or dissolved — but not in solid form
ions are free to move so they carry a charge - have high melting points — giant ionic lattices held together by strong electrostatic forces
- they dissolve in water
water molecules are polar so they charged parts pull ions away from lattice causing it to dissolve
what are ionic crystals
they’re giant lattices of ions
ex. Cl- — Na+
what are the charges for sulphate, hydroxide, nitrate, carbonate, and ammonium
sulphate — SO4^2-
Hydroxide — OH-
Nitrate — NO3-
Carbonate — CO3^2-
Ammonium — NH4+
what’s a macromolecular structure
giant covalent structures that have a huge network of covalently bonded atoms
ex. carbon — graphite, diamond
what are the properties of graphite
weak bonds between the layers in graphite are easily broken so sheets slide over eachother
they have delocalised electrons that are free to move and carry charge so it’s a conductor
layers far apart so graphite has low density and is used to make strong lightweight sports equipment
graphite is insoluble in any solvent cuz covalent bonds are too strong to break
rxplain the properties of a diamond
- high MP
- extremely Hard
- vibrations travel easily through the stiff lattice i it’s a good THERMAL conductor
- can’t dissolve in any solvent cuz covalent
- cut diamond to form gemstones so the structure lets it refract LIGHT a lot
what is dative covalent bonding
it’s where both electrons come from one atom
ex. NH4+ as the nitrogen atom donates a pair of electrons to a proton H+
this is represented with an arrow
what’s a covalent bond
a shared pair of electrons between two atoms
how does a single covalent bond differ from a double covalent bond
a single bond only contains one pair of shared electrons while a double bond contains two pairs of electrons
what caused a permanent dipole
the difference in electro negativity between two atoms
what are the three types of intermolecular forces
- Van Der Waals
- Permanent dipole dipole forces
- Hydrogen bonding
explain van der waals forces
VDW forces cause all atoms and molecules to be attracted to eachother
they’re when electrons in charged clouds move around quickly and when they move a little more to one side than the other they create a temporary dipole
this dipole can cause another temporary dipole in opposite direction on a neivoring atoms
then the second dipole causes a third dipole and continues like a domino effect
because the electrons are constantly moving the dipoles are being created and destroyed all the time even though the dipoles keep changing the overall effect is for atoms to be attracted to eachother
what effects the VDW forces
the shape the larger the molecule the stronger the forces
straight chain molecules have stronger forces than branched ones
stronger forces means higher BPs
what does hydrogen bonding bon with
Fluorine
Nitrogen
Oxygen
because they’re very electronegative
properties of hydrogen bonding
HIGH MELTING AND BOILING POINTS
what’s the properties of a metallic bonding
high melting points cuz of strong electrostatic attraction between the positive ions and the delocalised sea of electrons
number of delocalised electrons per atom affects MP the more there are the stronger the bonding and MP wil be
the delocalised electrons pass kinetic energy to eachother making good thermal conductors
good electrical conductors because delocalised electrons move freely and carry charge
metals are insoluble because of strength of metallic bonds
explain the MP, state at room temp, conducts electricity in solid or liquid, and if it’s soluable in water
IONIC BONDING
HIGH MP
at room temp it’s SOLID
doesn’t conduct electricity when in solid but it does in liquid form
it’s soluble in water
explain the MP, state at room temp, conducts electricity in solid or liquid, and if it’s soluable in water
simple covalent
LOW MP (covalent bonds don’t break but the intermolecular bonds do)
usually liquid or gas at room temp
doesn’t conduct electricity at all
depends how polarised it is to be soluble
explain the MP, state at room temp, conducts electricity in solid or liquid, and if it’s soluable in water
large covalent
HIGH MP
solid at room temp it’s
doesn’t conduct at all except graphite
not soluble
explain the MP, state at room temp, conducts electricity in solid or liquid, and if it’s soluable in water
metallic
High MP
solid at room temp
conducts electricity either way
not soluble
