bonding Flashcards
(25 cards)
what common compound ions are there?
ammonium- NH4+
carbonate- CO32-
hydroxide- OH-
nitrate- NO3-
sulfate- SO42-
describe a giant ionic lattice
a structure made up of the same basic unit repeated over and over
what are the properties of ionic compounds?
-conduct electricity when molten or dissolved, ions in liquid are free to move
-high m.p and b.p, giant ionic lattices are held by strong electrostatic forces
-dissolve in water which is polar, water molecules pull ions away from lattice
what is ionic bonding?
bond between oppositely charged ions.
what is covalent bonding?
shared pair of electrons between non-metals.
what is a co-ordinate bond?
one of the atoms provides both of the shared electrons.
what is a charge cloud?
an area where you have a big chance of finding an electron.
why do charge clouds repel?
electrons are negatively charged, so repel until they’re far apart as possible.
what is valence shell electron pair repulsion theory?
lone-pair clouds repel more than bonding-pair charge clouds so bond angles are smaller because bonding pairs are pushed together by lone-pair repulsion
state molecular shapes with no lone pairs, and their bond angle/s.
linear- 2 bonded pairs, 180
trigonal planar- 3 bonded pairs, 120
tetrahedral- 4 bonded pairs, 109.5
trigonal bipyramidal- 5 bonded pairs, 120 and 90
octahedral- 6 bonded pairs, 90
state molecular shapes with lone pairs, and their bond angle/s.
trigonal pyramidal- 3 bonded pairs, 1 lone pair, 107
bent (non-linear)- 2 bonded pairs, 2 lone pairs, 104.5
seesaw- 4 bonded pairs, 1 lone pair, 102, 86.5
t-shape- 3 bonded pairs, 2 lone pairs, 87.5
square pyramidal- 5 bonded pairs, 1 lone pair, 90
square planer- 4 bonded pairs, 2 lone pairs, 90
what is electronegativity?
the ability to attract the bonded electrons in a covalent bond.
what does non-polar mean in bonds?
atoms have equal electronegativities so electrons equally attracted to nuclei.
what does polar mean in bonds?
atoms have different electronegativities so electrons are pulled to the more electronegative atom.
what is a dipole?
a difference in charge between the 2 atoms caused by a shift in electron density in the bond.
what creates a permanent dipole?
if charge is distributed unevenly.
what are intermolecular forces?
weak forces between molecules.
what are van Der Waals forces?
causes all atoms and molecules to be attracted to each other.
do all van der waals have the same strength, what affects it?
larger molecules have larger electron clouds, so stronger van Der Waals forces.
long, straight molecules can get closer together than branched ones.
what happens when you put an electrostatically charged rod next to a jet of water?
it will move towards the rod because the water is polar and has a permanent dipole. the polar molecules can turn around so oppositely charged end is attracted towards the rod.
what is hydrogen bonding?
the strongest intermolecular force, happens when hydrogen is covalently bonded to F, N or O, as they are very electronegative, draw the bonding electrons away from the H atom.
what happens when water cools to form ice?
hydrogen bonds arrange themselves into a regular lattice, the distance between liquid molecules is greater than in ice so ice is less dense.
what are the properties of simple compounds?
-don’t conduct electricity, no free ions
-low m.p, weak forces easily broken
-dissolve in water depending on how polar
what is metallic bonding?
a lattice of positively charged ions surrounded in a sea of delocalised electrons.
