topic 3: bonding and structure Flashcards
how does hydration affect the soubilty of ionioc compounds in water
hydration helps ionic compounds to disscolve. water molecules surrouns and attract to the ions, which helps to break apart the compound’s lattic strucutre
in wt way does graphene differ from graphite in terms of strucutre and thickenss
graphene is a single layer sheet of carbons atoms, while graphite consists of multiple layers of graphene stacked together
3 porpterties of graphite
conudcuts electeicity
layers slide, making it a lubricant
high melting point
diff between a polar covalent bond from a nonpolar covalent bond
a polar covalent bond has unequal sharing of electrons due to differing electronegativity, creating partial charges. a nonpolar bond has equal sharing with no charge seperation
wt happens to sodium ions and chloride ions during electroyslsi of sodium chloride
sodium ions move to the negative elctrode and gain electrons, forming sodium atoms
chloride ions, move to the postive electrode and lose electrons forming chlorine gas
relationship between the charge-to-radius ratio of cations and the melting temp of metals
a greater charge-to-radius ratio of the cation leads to a stronger attraction for delocalized electrons, resulting in a higher melting temp
how does electronegativty influence bond polarity in a covalent bond
electronegtivity difference causes unequal sharing of electrons creating polarity in covalent bond. large differnces lead ot greater polarity
wt role does cations play in the metallic bonding process
attract delocalized electrons, forms a closely packed, help conduct kinetic energy
how does the size and charge of cations influcence their polarising power
smaller size and higher charge increases a cations’s polarising power cuz they result in higher charge density
wt is polarisation in the context of ionic bonding
polarization is when a cations distorts the electrons cloud of an anion an ionic bond
5 properties of ionic compounds
high melting points, brittle, poor conductors when solid, good coductors when moleten, often soluble
why do ionic compounds hve high melting temps
cuz they hve strong electrostatic forces between oppositely charged ions in a lattice strcutre
wt causes the briteleness of ionic solids when stress is applied
stress causes the ions to slide. ions of the same charge align, leading to repulsion and breakage
wt is ionic bonding
the attraction between oppositely charged ions
diff between a dative covlent bond and a regular covalent bond
in dative bonds, one atom provides both electrons for the bond, while in regular covalent bonds, each atom gives one elctron
wt r the 2 factors that influcence the bond angles in a molecule according to the electron-pair repulsoin theory
repilsion between electron pairs
no of bond pairs and lone pairs aroudn the central atom
significance of lone pairs in determining molecular shape
lone pairs repel more than bonding pairs. they influnce the bond angles and overall shape of a molecule
5 characteristic of giant metrallic lattices
high metling points
good electrical/thermal conductor
malleable
ductile
regular arrangement of positve metal ions
surrounded by delocalized electrons
why do smaller ions need more energy to seperate compared to larger ions
smaller ions hve a higher charge density, leading to stronger electrostatic forces and needing more energy to overcome interactions
3 diff between ionic lattices and giant covalent lattices
structure - ionic lattices hve ions, covalent lattices hve atoms
bonding - ionic lattices hve electrostatic forces, covalent lattices hve covlent bonds
properties - ionic lattices r brtieel, conduct electrocity when moltent, covalent lattices r hard and has high melting point
4 exmaples of giant covalent subtances
diamond, graphite, graphene, silicon(IV)dioxide
wt r the factods that affect the strength of ionic bonding
ionic charge - higher charges lead to stronger bonds
ionic size - smaller ions form stronger bonds
