chapter 6 Flashcards
what are the features of a linear shape
a linear shape has 2 electron areas and has 180 degree bond angle
what are the features of a trigonal planar shape
a trigonal planar shape has 3 electron regions and has 120 degree bond angle between atoms
what are the features of a tetrahedral shape
a tetrahedral shape has 4 electron regions and a 109.5 degree angle between atoms
what are the features of an octahedral shape
has 6 electron regions and has 90 degree bond angles
what is the electron pair repulsion theory
this theory suggests that as electrons repel each other the arrangement of electrons minimises the repulsion and so the bonded atoms stay in a definite shape.
what happens of there are lone pairs of electrons
the molecules form weird shapes
what are the features of a trigonal bi pyramidal
5 electron regions 2 90 degree bond angles and 3 120 degree bond angles
what are the features of a non linear shape
2 BP 2 LP and an 104.5 degree bond angles
what are the features of a trigonal bi pyramidal molecule
1LP 3 BP and 10 7degree bond angles
what are the 3 types of intermolecular forces
London forces , permanent dipole-dipole interactions and hydrogen bonding
what is the strongest intermolecular forces
hydrogen bonding
what is the weakest inter-molecular forces
London forces
what is the second strongest intermolecular force
permanent dipole-dipole interactions
what are London forces (induced dipole dipole interactions)
weak intermolecular forces
exist in all molecules
movement of electrons produces a changing dipole in a molecule
can be attracted to the opposite charged dipole
what are permanent dipole dipole interactions
forces of attraction that appear between permanently differently charged polar molecules
what is hydrogen bonding
hydrogen bonding is the attraction between a slightly negative hydrogen and another slightly positive element or an element ith lone pairs of electrons
what are the anomalous properties of water
solid ice is less dense then the liquid water relatively high boiling , melting points for a covalently bonded molecule relatively high surface tension and viscocity
why is ice less dense then water
ice is less dense then water as with 2 lone pairs on the oxygen and 2 hydrogens each water molecule can form 4 hydrogen bonds that form an open tetrahedral shape.This has lots of holes that decrease the density of the water when ice melts the lattice collapses
why has water got a relatively high melting boiling point
Water contains all 3 types of intermolecular bonds (London forces, induced and permanent dipole dipole interactions)
