chapter 2 Flashcards
(13 cards)
what is ionic bonding and how strong are they compared to other bonding types
ionic bonds are the electrostatic attraction between between ions of opposite charges
strength wise: covalent bond>ionic bond>covalent bond
what are the compound ions
carbonate: CO3^2-
nitrate:NO3^1-
hydroxide:OH^1-
sulfate:SO4^2-
ammonium:NH4^1+
what are cations and anions
cations are positive ions
anions are negative ions
what are ionic lattices
ionic compounds have giant ionic lattice structures
this means that the structure is made of repeating units of identical structure
different compounds have very different lattices
what are the properties of ionic lattices
they dissolve in water because water is polar
they conduct when molten or dissolved because the ions can carry a charge
they’ve high melting points because the ionic bonds are strong
why’re covalent bonds so strong
the electrons that are being shared are attracted to the nucleus of both atoms
molecules must have covalent bonds holding the atoms together
whats the correlation between bond strength and bond length
shorter covalent bonds are stronger than longer covalent bonds
the length of a covalent bond decreases when more electrons are involved in the bond-single bonds are weaker than double bonds
single bonds are longer and weaker than double bonds
what is a dative covalent bond
a covalent bond in which both electrons in the bond come from one atom, they’re sometimes called coordinate bonds
E.g ammonium ions NH4^1+ has a dative covalent bond to one of its hydrogens and both electrons in the covalent bond are from the nitrogen
what are orbitals
a region of space where there is a 95% chance of finding an electron
can be viewed as charge clouds-regions of space where the electrons move around
how does repulsion play a part in shapes of molecules
electrons are all negatively charged so they repel each other
electrons will move as far away from each other as possible
this determines geometry of a molecule
whats the difference between lone pairs and bonding pairs
lone pairs are held closer to the nucleus of an atom, so therefore they’ll repel each other more as they’re physically closer
the trend in repulsion strength (most to least) is:
lone pair-lone pair
lone pair-bonding pair
bonding pair-bonding pair
what are the geometry names of molecules and what are their angles
linear- when the central atom has 2 electron pairs-180 degrees
trigonal planar- when the central atom has 3 electron pairs-120 degrees
tetrahedral-when the central atom has 4 electron pairs-109.5 degrees
trigonal bipyramidal- central atom has 5 electron pairs-120 degree angle around equator and 90 degree angle from equator to apex
octahedral- central atom has 6 electron pairs-90 degrees angle
