3. Chem Bonding Flashcards
(12 cards)
VSEPR Theory
- electron pairs in the valence shell of the central atom will arrange itself as far as possible from ro to min repulsion
- lp-lp>lp-bp>bp-bp repulsion
Q: “Use VSEPR theory to predict shape of ion”
- __ lp, __bp
- shape is __
- (VSEPR 2 statements)
exp how id-id arises
- electrons constantly moving
- asymmetrical e cloud –> instantaneous dipole
- which induces another dipole on the neighboring molecule
- electrostatic attraction btw instantaneous and induced dipole
exp how pd-pd arises
strong electrostatic attraction btw opp charged ends of dipole
exp how HB arises
- H bonded to FON has large δ+
- strong electrostatic attraction btw H and lone pair of e on FON on neighboring mol
define ionic/covalent/metallic bonding
strong electrostatic attraction btw
I: cations & anions
C: nuclei of atoms & shared pair of e
M: cations & sea of delocalised e
exp why Mg metal deforms but Mg oxide shatters
Mg: cation layers slide but sea of e move to prevent repulsion
MgO: cation layers slide, similar charged ions come tgt, repulsion
which atoms are non-polar and polar
non-polar: CHPB
(cute housing promotion board)
polar: FONCl
(full of nonsense Chlorine)
why does dative bonding occur
X has lone pair of e avail for donation
Y is e deficient, has empty and energetically accessible d-orbitals to accept the lone pair of e
why larger coordination num + coordination num definition
def: no. of e that immediately surround an ion of opp charge within crystal lattice
larger ion size, more ions can be packed ard it
exp whats a sigma and pi bond
atomic orbitals overlap head-on / side-on
exp why AlF3 is predominantly ionic but AlCl3 is predominantly covalent
Al3+ high charge density, high polarising power, able to distort e cloud of highly polarisable Cl- to a large extent
(polarising power of cation + polarisability of anion)
