chem struc & bonding Flashcards
ionic bond def: __________________________ forces of __________________ between _____________ charged ______ in a _____________________ structure
strong electrostatic, attraction, oppositely, ions, giant ionic lattice
ionic bond def:
strong electrostatic forces of attractions between oppositely charged ions in a giant ionic lattice structure
ionic bonds are usually between
metal & non-metal
in same period, size of cation is always __________ than size of anion (cus cations ______ electrons & anions ______ electrons)
smaller, lose, gain
ionic compounds have
giant ionic lattice struc
when ions come tgt, they arrange themselves in a continuous 3d lattice of _____________cation and anions, which _____________ attractive forces between _____________ charged ions & ____________ repulsion between ____________ charged ions
alternating, maximises, oppositely, minimises, similarly
ionic bonds are generally ________ and a _______ amt of energy is needed to break such bonds
strong, large
the ____________ the charges of ion, the _____________ the ionic bonds
greater, stronger
the ___________ the ionic radius, the ___________ the ionic bonds
smaller, stronger
ionic radius for cations & anions ____________ across period (cus no. of protons increase –> __________ pull to nucleus) & ____________ down grp (no. of electron shells)
decreases, stronger, increases
IMPT: how to ans qns with reference to structure & bonding: which ionic compound have stronger ionic bonds
1. do they have giant ionic lattice?
2. compare cation & anion charges (__________ charge, _________ bonds)
3. compare ionic radii of cation & anion (___________ radii, ____________ bonds)
4. hence, ………. is stronger as _______ energy is needed to ______________ the __________ ionic bond
greater, stronger
smaller, stronger
more, overcome, stronger
more protons –> ___________ electrostatic forces of attraction –> shell shrinks –> _________ to nucleus –> radii ____________
greater, closer, smaller
with reference to structure & bonding, predict if …… has a higher/lower boiling point than …….
- compare both lattice structures (ionic/not)
2.compare charges (greater charges stronger bonds) - compare ionic radii (smaller radii, stronger bonds)
ionic compounds hav high boiling & melting pts bc a _________ amt of energy is needed to _____________ the _________ electrostatic forces of _________________ between opp. charged ions
large, overcome, strong, attraction
ionic compounds r gd conductors of electricity in MOLTEN & AQUEOUS states but non-conductors in SOLID state as in the molten/aqueous state, there are _______ mobile ions to act as _______________________________ to conduct electricity, but in solid state ions can only ___________ abt their_______ positions–> no ______________________________ to conduct electricity
free, mobile charge carriers, vibrate, fixed, free mobile ions
ionic compounds r generally soluble in __________ but insoluble in _____________ ___________ such as oil and turpentine
water, organic solvents
ionic compounds r hard cos in an ionic _______, opp. charged ions r held tgt by ________ ____________________ ________ of attraction
solid, strong electrostatic forces
ionic compounds r brittle cos when stress is applied on an ionic _________, it causes _________ of layers of ions, making ions of __________ charges to come tgt, & resultant _____________ __________ the ionic structure
lattice, sliding, similar, repulsion shatters
ionic compounds r used in refractories as they can withstand _______ temps
high
metallic bonds r formed when metal _______ ______ valence electrons to from _________. these valence electrons are ______________
atoms lose, cations, delocalised
metallic bonds def: metallic bonds are _________ _______________ __________ of attraction between metal __________ & the _______ of _________________ electrons in a __________ ______________ lattice
strong electrostatic forces, cations, sea of delocalised, giant metallic
metallic bonds def: metallic bonds are
strong electrostatic forces of attraction between metal cations and sea of delocalised electrons in a giant metallic lattice
delocalised electrons are capable of ____________ _________ between the metal cations
moving freely
metals hav __________ _____________ structure
giant metallic
metallic bonds are generally _________ & _________ amt of energy is needed to break them
strong, large
the ____________ the no. of valence electrons contributed to sea of ________________ electrons per _______, the _____________ the ____________ bonds (eg metallic bond in magnesium is stronger than sodium cos mg has 2 valence electrons per atom compared to 1 per sodium atom)
greater, delocalised, atom, stronger, metallic
the larger the ____________ radius, the ____________ the _____________ bonds (cos delocalised electrons less strongly held by nuclei cus it’s furthest away-> attraction between electrons & cations weaker)
metallic, weaker, metallic
ionic radius for cations & anions decreases ___________ ___________ & increases _________ _________
across period, down group
metals have high boiling & melting pts. bc _________ amt of energy is needed to overcome _________ ____________________ _________ of attraction between metal __________ & _______ of ____________________ ______________
large, strong electrostatic forces, cations, sea, delocalised electrons
metals are gd conductors of electricity cos there’s a ______________ of ________________ ________________ to act as mobile charge ___________ to conduct electricity
presence, delocalised electrons, carriers
metals r gd thermal conductors: when heat applied to 1 end of metal, ____________ energy of the _______________ at that end increases & the energy is transferred throughout rest of metal by the ________________ electrons to ________ parts of metal
kinetic, electrons, delocalised, other
metals are malleable & ductile bc when force is applied, the __________ of ________ can easily __________ _______ each other w/o breaking the metallic bond; the metallic bonds are easily ________________ & the __________________________ lattice is restored
layers, atoms, slide over, reformed, giant metallic
malleable def: ability to be _______________/____________ ______ sheets w/o cracking
hammered, pressed into
ductile def: ability to be _____________________ into a _______________________
drawn out, thin wire
def of alloys: a ___________ of a metal & another ______________(usually metals)
mixture, element
def of alloys:
a mixture of a metal and another element
alloys are much ____________ & __________ than _______ metals, cos the arrangement of atoms is ________________ by the insertion of atoms of a slightly _____ size –> __________________ in structure prevents rows of atoms from _________ over each other
stronger, harder, pure, disrupted, diff, irregularity, sliding
formation of covalent bonds involves __________ of _______________ between ______ to form a ______________
sharing, electrons, atoms, molecule
def: covalent bond is the ________________ __________ of _______________ between the ________ _______ of electrons and the _____________ ___________ _______ of both _____ in the bond
electrostatic forces, attraction, shared pair, positively charged nuclei, atoms
lone pair refers to _____________ _____ _____________ in covalent bonding
electrons not involved
strength of covalent bond depends on extent of _____________ ____________
orbital overlap
more effective the orbital overlap, ____________ the covalent bond
stronger
covalent bonds are _________ and a ________ amt of ___________ is needed to break such bonds
strong, large, energy
bond length: distance (in nm) between the 2 _______ in a covalent bond
nuclei
shorter the bond length, ____________ the bond
stronger
greater the bond energy, ____________ the bond
stronger
generally, bond strength: trip bond __ double bond __ single bond
> ,>
ANS SKILL: which covalent bond is stronger
1. atomic radius of the 2 atoms (___________ ->stronger)
2. more effective ____________ ____________ between xx atoms
3. hence leading to ___________ covalent bond
- smaller
- orbital overlap
- stronger
egs of GIANT MOLECULAR STRUCTURES:
- diamond
- graphite
- silicon
- silicon dioxide
egs of SIMPLE MOLECULAR STRUCTURE:
H2, N2, H2O, NH3
structure of diamond (C), silicon dioxide (SiO2), and silicon (Si): diamond has a _________ _____________ structure where each __________ atom is joined by strong _____________ bonds to ______ other atoms in a _______________ arrangement
giant molecular, carbon, covalent, four, tetrahedral
allotrope def: _______ forms of the _________ _______________ with _______________ chemical properties but ________ physical properties
diff, same element, similar, diff
diamond is an _____________ of carbon
allotrope
diamond has ______________ strong _______________ bonds between _______ resulting in a giant _____ molecular structure
numerous, covalent, atoms, 3D
diamond has a very _______ ___________ ______ cos a ______ _________ amt of energy is needed to __________________ the _____________ __________ ______________ bonds between ________
high melting pt, very large, overcome, numerous strong covalent, atoms
diamond is hard cos of the ___________________________________________ between atoms
numerous strong covalent bonds
diamond is a non-conductor of electricity cos of the _____________ of __________________ _______________ and ________ mobile _______ to conduct electricity ( all the electrons used in covalent bonding)
absence, delocalised electrons, free, ions
diamonds are _______________ in water
insoluble
diamonds used as abrasives due to ________ melting points and _____________ (eg diamond tipped tools for cutting)
high, hardness
silicon (Si) has a similar structure to diamond-> _____________ ______________ properties as diamond
similar physical
silicon dioxide consists of each silicon atom covalently bonded to ____ ____________ atoms in a _______________ structure and each ___________ atom covalently bonded to ____ silicon atoms
4 oxygen, tetrahedral, oxygen, 2
silicon dioxide’s phys properties resemble those of diamond:
- hard
- high melting & boiling pts
- non-electrical conductor
- insoluble in water
graphite is a __________________________, ______________ structure
giant molecular, layered
graphite: adjacent layer held tgt by ______ intermolecular forces (dotted lines)
weak
Graphite: in each layer, each carbon atom is ________________ _________ to _____ other atoms
covalently bonded, 3
graphite is another _______________ of carbon
allotrope
Graphite: carbon _______ r arranged in _______________ flat __________ layers
atoms, hexagonal, parallel
graphite has _________ melting point cos a ____________________ amt of energy is needed to overcome the ________________________________________ between atoms
high, very large, numerous strong covalent bonds
graphite is ______________________________ parallel to layers but ___________________ perpendicular to layers
cos only ______ valence electrons of each C atom is used for bonding-> 4th non-bonding electron is _____________________ over whole layer & able to act as ________________ charge carriers
gd electrical conductor, non-conductor, 3/4, delocalised, mobile
graphite is soft & slippery cos the adjacent __________ r held by _____________________________ forces which are _________ overcome -> layers slide over each other _________
layers, weak intermolecular, easily, easily
graphite is ______________ in water
insoluble
graphite used as ____________ (eg used in hot machines to reduce friction)
lubricant
iodine has a ____________ molecular structure
simple
PHYSICAL properties of simple molecular substances
_____ melting & boiling pt cus ________ amt of energy needed to overcome _________________________ forces of attraction between molecules
low, small, weak intermolecular
iodine atoms r bonded by __________ covalent bonds within each ______________ but separate ______________ r attracted by _______ intermolecular forces of attraction
strong, molecule, molecules, weak
PHYSICAL properties of simple molecular substances
__________________ of electricity cos there’s an ______________ of __________________________& ________________________ to conduct electricity
non-conductor, absence, free mobile ions, delocalised electrons
PHYSICAL properties of simple molecular substances
____________ in water, but soluble in _______________________ (eg benzene)
insoluble, organic solvents
ANS SKILL: BOILING PT OF SIMPLE VS GIANT MOLECULAR SUBSTANCE
1. x has a lower boiling point than y
2. x has a ________ molecular structure with ________ intermolecular forces of attraction between x molecules
3. y has _________ molecular structure with ____________________________ covalent bonds between y ________
4. _________ energy is needed to ________________ the ____________________________________ bonds in y than the ___________________________ forces of attraction between x molecules
- simple, weak
- giant, numerous strong, atoms
- more, overcome, numerous strong covalent, weak intermolecular
ANS SKILL: COMPARING BOILING PT OF SIMPLE MOLECULAR SUBSTANCES
1. x has much higher boiling point than y
2. both x & y have ___________ molecular structures with ________ intermolecular forces of _______________
3. x has __________ electron cloud (region of electrons arnd a molecule/atom)-> ____________ & more ________________ intermolecular forces of attraction which needs __________ energy to overcome
- simple, weak, attraction
- larger, stronger, extensive, more
electron cloud refers to
region of electrons arnd molecule/atom
larger the Mr –> __________ the electron cloud –>___________ & more _______________ ___________________ forces of attraction
larger, stronger, extensive, intermolecular
ANS SKILL: IONIC VS COVALENT COMPOUND MELTING PT
1. state _____________ of each compound (what is giant _________ structure, what is __________ molecular structure
2. the strong _________ bonds in xx needs a ________ amt of energy to overcome it -> _________ melting pt
3. a small amt of energy is needed to overcome the ____________________________________________ between yy molecules -> _______ melting pt
- structure, ionic, simple
- ionic, large, high
- weak intermolecular forces of attraction, low
some molecules (like water) have a type of intermolecular force of attraction called ________________ bonds
hydrogen
hydrogen bonds r generally __________ than other ____________________ forces of attraction, but they’re still weaker than ___________, ____________ or __________ bonds
stronger, intermolecular, covalent, metallic, ionic
hydrogen bonds r between
H and O atom (H connect to O)
