chem test Flashcards
2 bonded atoms, 0 lone pairs
linear, 180, 2 total electron domains
domain
a location of a bond or a lone pair of electrons (double and triple bonds only count as one domain)
3 bonded atoms, 0 lone pairs (Boron triflouride; BF v 3)
trigonal planar, 120, 3 total electron domains
2 bonded atoms, 1 lone pair (Nitrate Ion; NO v 2 ^ -1)
bent, 118, 3 total electron domains
4 bonded atoms, 0 lone pairs (Methane; CH v 4)
tetrahedral, 109.5, 4 total electron domains
3 bonded atoms, 1 lone pair (Ammonia; NH v 2)
trigonal pyramidal, 107, 4 total electron domains
2 bonded atoms, 2 lone pairs (water; H v 2 O)
bent, 104.5, 4 total electron domains
5 bonded atoms, 0 lone pairs (PCl v 5; Phosphorus pentachloride)
trigonal bipyramidal, 120 and 90, 5 total electron domains
6 bonded atoms, 0 lone pairs (Sulfur nexaflouride; SF v 6)
octahedral, 90, 6 total electron domains
diatomic ions, and what elements can form them
ions made up of two atoms of the same element. They are always found together in a compound. The following elements can form diatomic ions: H, N, O, F, Cl, Br, and I.
monatomic ions
are ions formed from a single atom. They can be either positive or negative.
cation
ion that has lost electrons and has a positive charge (cat–> PAWsitive)
anion
ion that has gained electrons and has a negative charge
ion
An ion is an atom or a group of atoms that has gained or lost electrons, resulting in a positive or negative charge
what follows single element cations? for example Na ^ +
the name of the element is used followed by the word word “ion”
Na ^ + = sodium ion
what follows single element anions? for example Cl ^ -
the name of the element is used followed by the suffix “-ide”
Cl ^ - = chloride ion
how do you write a single element transition metal ion? for example Fe ^ 3+
you have to include the charge in roman numerals following the element name
Fe ^ 3+ = iron (III) ion
NH v 4 ^ +
ammonium
SO v 3 ^ 2-
sulfite
SO v 4 ^ 2-
sulfate
OH -
hydroxide
PO v 4 ^3 -
phosphate
O v 2 ^2 -
peroxide
how do you write and name ionic bonds? for example Na+Cl-
criss cross their charges down (to achieve neutrality)
Subscripts must be the lowest ratio when canceling charges.
positive metal ion always comes first
drop the second syllable of the negative/anion element and subsitute with “-ide”
Na+Cl- = NaCl
sodium + chlorine = sodium chloride
ionic compounds must have an overall ______ charge
neutral (charge of 0)
what are ionic compounds made of?
- Ionic compounds are formed when positive and negative ions combine.
- have a metal and a nonmetal
how do you name transition metal ionic compounds? for example CuO vs Cu v 2 O
you include the roman numeral in the name
CuO = copper (I) oxide
Cu v 2 O = copper (II) oxide
polyatomic ions
most polyatomic ions are covalent
ions that are made with more than two elements (SO v 4 ^ 2- = sulfate)
- when you do the drop and switch (criss cross), use parenthesis
ex: Ca ^ 2+ + NO v 3 ^ -1 = Ca(NO v 3) v 2
use both names –> calcium nitrate
if there are two polyatomic you use both of them as well –> ammonium oxalate
ionic compounds with transition metals; for example
Cu ^ +2 Cl ^ -1
CuCl v 2 = copper (II) chloride
make sure to specify the charge of the transition metal with roman numerals
(re criss crossing )
covalent compounds are made of ______
two or more nonmetals SHARE electrons
how do you name covalent bonds? for example SO
prefixes are used to indicate the number of atoms in each element
- end second element with “-ide”
- mono is NOT used for the first element
- sulfur monoxide
prefixes
1- mono
2- di
3- tri
4- tetra
5- penta
6- hexa
7- hepta
8- octa
9- nona
10- deca
VSEPR
valence shell electron pair repulsion
- The model states that electron pairs will repel each other such that the shape of the molecule will adjust so that the valence electron-pairs stay as far apart from each other as possible.
- VSEPR theory allows more accurate predictions of molecular shape
intermolecular
attractive force between molecules (dipole= polarity)
different types of IMF (intermolecular forces)
put them from strongest to weakest
hydrogen bonding
dipole-dipole attraction
london dispersion attraction
dipole-dipole attraction
occurs between : partially oppositely charged ions
relative strength: strong
hydrogen bonding
occurs between : H atom and O, N or F atom
relative strength: strongest of the dipole- dipole attraction
london dispersion attraction
occurs between: temporary or induced dipoles
relative strength: weakest
metallic bond diagram
sea of e- (reason for conductivity)
lone pair
a pair of valence electrons that are not shared between atoms (aka nonbonding pair or unshared pair )
single pair
bond between two atoms by one pair of electrons
double pair
bond between two atoms by two pairs of electrons
triple bond
bond between two atoms by 3 pairs of electrons
what type of bond are
H v 2 O
NaCl
H v 2 O = bent because it has one bond
- covalent, polar
NaCl = linear because it only has 2 pairs
- ionic
types of covalent bond types
polar and nonpolar
polar
typically between two different elements
- electrons are more on one side than the other (toxic bf)
Sharing of electrons: unequal attraction for electrons so the sharing is UNEQUAL
electronegativity difference: 0.4-1.7
_____>
examples: HF H F
non polar
Sharing of electrons: shared equally between the two atoms
Electronegativity difference: less than 0.4
examples: Cl Cl—–> Cl v 2
octet rule
atoms prefer to have 8 electrons in the valence shell
lewis dot diagrams
- atomic models which show valence electrons and can be used to predict bonding
- bonding occurs when atoms try to reach octet
ionic compound (characteristics)
- lattice structure of atoms, transfer of electrons
conductivity: electrons are FIXED, no conductivity in solids, conductivity in liquid
solubility: many are soluble in H v 2 o
state of matter: crystaline solids
other: large electronegativity difference between ions (greater than 1.7)
electrons: transferred from metal to non-metal. elements attracted by opposite charges
covalent compound (characteristics)
- sharing of electrons
conductivity: no conductivity
solubility: most are non soluble in H2O, soluble in nonpolar solvents
state of matter: liquid or gas at room temperature
other: small or no difference in electronegativity between atoms (less than 1.7: polar 0.4-1.7; non-polar 0-0.4)
electrons: shared between 2 nonmetals
Metallic compound (characteristics)
- sea of electrons (e-)
conductivity: good conductivity
solubility: most do not dissolve in H2O, some react with H2O
state of matter: solid at room temperature, mercury at room temp is a liquid
other: most metallic bonds are made of the same atoms so electrons are shared equally
- alloys are mixtures of metals
alloys
mixtures of metals
electronegativity
the tendency of an atom to attract electrons to itself in a chemical bond
what occurs when salt dissolves in water?
the molecules mix amongst eachother
