Ionic Compounds/Polyatomic Compounds (Naming system) Flashcards
is the nonmetal or the metal the cation?
metal
is the nonmetal or the metal the anion?
nonmetal
True or False: Do the elements in ionic compounds have to not cancel out?
False, it needs to cancel out
True or false: Does the cation in an ionic compound ALWAYS come first? And does the anion ALWAYS stay at the end?
yes, yes
Ionic Nomenclature Rules
- Keep the name of the Cation (it will stay the same)
- Add the -ide suffix to the anion of the compound
(cut off the end of the elements name to add -ide)
Roman Numeral Rules
- Transition metals can have multiple charges depending on the ion produced
- Determine the charge and add it after the name of the cation.
- Will write that charge in roman numerals between the parenthesis
- You can determine the charge of the cation by knowing the charge of the anion and vice versa
- Since the molecules have to make a neutral charge, they must all ADD up to 0
- the anion will have -ide at the end
Latin Naming System
- Find out if the ions in the compound is lesser or greater one (like if an element can be both +2 or +4, find out which one it is)
- After finding it out, add -ic –> higher charge and -ous –> ous
*usually applies when the ion is a cation(metal) - Add -ide to the anion
Can the Latin and Roman Numeral Naming System be used together?
yes
What are polyatomic ions
Covalently bonded elements that form a single unit that acts as the anion in the ionic compound
Polyatomic Rules for Naming
- You take the name of the cation
- And you add the polyatomic ion name
- Nothing else happens to it
What is the naming system for the Halogens in Polyatomic ions?
1 oxygen = add hypo- (at the beginning) and -ite (at the end)
2 oxygens = add -ite
3 oxygens = add -ate
4 oxygens = add per-(at the beginning) and -ate (at the end)
Octect Rule
form bonds to have 8 electrons around them (have 2 in each side)
Do compounds have one metal and one nonmetal or two nonmetals?
two nonmetals
Defining Molecular Compound
- A molecular compound is made up of covalent bonds which involves the sharing of electrons
- Covalent bonds are usually between 2 nonmetals
Compounds Nomenclature Rules
- Use the -ide suffix on the second element (ALWAYS)
- If there’s only 1 element of the 1st atom, you DONT need the mono prefix
- If the element starts with AND the prefix ends with “a” or “o”, you will usually drop the last vowel of the prefix
name the prefixes for the covalently bonded compounds
mono -1
di - 2
tri - 3
tetra - 4
penta - 5
hexa - 6
hepta - 7
octa - 8
nona - 9
deca - 10
Defining Acids
Dissociate in water to produce H+ ions and some anions.
Equation that makes up: Binary Acids
Hydrogen + a Halogen
Equation that makes up: Oxyacids
Hydrogen + Polyatomic anion
Naming System for Binary Acids
- Acids are named by their ANION (so ignore the H)
- An element (anion) with the “ide” suffix will change to “ic” and have the prefix “hydro-”
- Then add the word “acid” after you’re done.
Naming System for Oxyacids
- A polyatomic with the “-ate” suffix will change to “ic”. add the word “acid” after you’re done
- A polyatomic with the “-ite” suffix will change to “-ous”. add the word “acid” after you’re done
- Then add the word “acid” after your done
What are covant bonds
some valence electrons shared between atoms
what are ionic compounds
complete transfer of 1 or more electrons from
one atom to another (one loses, the other gains)
forming oppositely charged ions that attract one
another
How to know the electron negativity difference?
if the difference is:
* greater than or equal to 1.9 : ionic
* greater than or equal to 0.5, but less than 1.9 : Polar covalent
* less than 0.5: Non-polar covalent
Bond Polarity
- A bond is polar if…
- What are the 2 common exceptions
- the 2 atoms involved are not the same
- C-H, and Cl-N bonds
True or False:
A molecule that contains polar bonds may or may not be polar, depending on its shape
True
Polar bonds
What makes molecules with nonpolar bonds a polar molecule?
if the central atom has one or more lone pairs
Polar bonds
What do you need to ask for if a molecule is polar if its bonds are polar?
- do the inidivudal bond polarities cancel them out?
- if so, the molecule is nonpolar. If not, then its polar
What is a general rule for finding if a molecule is polar or not?
symmetric = nonpolar
unsymmetric = polar
molecules w/ 3 atoms
- ____ bonds oppose (linear)
- ____ bonds oppose (linear)
- ____ bonds do not oppose (bent)
1.
- equal –> linear (x1 - x2 - x1)
- unequal –> linear (x1 - x2 - x3)
- equal –> bent ( x1 - x2 - x1)
the x mean the same or different molecules
Molecules with 4 atoms
- ____ bonds oppose in ____ planar arrangment
- ____ bonds in ____ planar arrangment
are these nonpolar or polar
- equal, trigonal –> nonpolar
- unequal, trigonal –> polar
Molecular Shapes
How can we predict the 3D structure of a moleucles just by …
ading up: bonded atoms + lone pairs
What determins the Shape of a molecule? - True or False?
Do bonded atoms and lone pairs take up less space and prefer to be closer to each other as possible
FALSE; bonded atoms and lone
pairs take up space and
prefer to be as far from
each other as possible
True or False:
does a central atom have 4 “things” around it? And what are those “things”
Yes it does. Things - is an atom or a lone pair of electrons
how do you find the # of “things” in a molecule?
atoms + lone pairs
Geometries
What is the:
1. # of things
2. geometry
3. bond angles
of linear
- 2 things
- linear
- 180 degrees
geometries
What is the:
1. # of things
2. geometry
3. bond angles
of trigonal planar
- 3 things
- trigonal planar
3.120 degrees
geometries
What is the:
1. # of things
2. geometry
3. bond angles
of tetrahedral
- 4 things
- tetrahedral
- 109.5
geometries
What is the:
1. # of things
2. geometry
3. bond angles
of trigonal bipyrimidal
- 5 things
- trigonal bipryimidal
- 120 and 90 degrees
geometries
What is the:
1. # of things
2. geometry
3. bond angles
of octahedral
- 6
- octrahedral
- 90 degrees
molecular geometries
what is the “shape” of the molecule defined by?
the geometry is often NOT the shape of the molecule
the positions of only the atoms in the molecules, not the lone pairs
Geometry vs. Shape
Within each (electron doman) geometry, there might be more than one ____
shape (molecular geometry)
Linear geometry: 2 things - true/false
in this geometry, there is only 1 molecule geometry: linear
Note: if there are only 2 atoms in the molecules, the molecules won’t be linear no matter what the geometry is
Part 1: True
Part 2: False - If there are only two atoms in the
molecule, the molecule will be linear no matter
what the geometry is.
Trigonal Planar geometry:
3 things
2 molecule geometries:
- Trigonal planar, if there are no lone pairs
- Bent, if there is a lone pair
Lone pairs and Bond Angle
Are lone pairs physically smaller or larger than atoms?
And is their repulsion smaller or larger? What happens to the bond in the angle of the molecule then?
- Lone pairs are physically larger than
atoms. - Therefore, their repulsions are
greater; this tends to decrease bond
angles in a molecule.
Tetrahedral geometry: 4 things
- There are three molecular geometries:
- Tetrahedral, if no lone pairs
- Trigonal pyramidal if one is a lone pair
- Bent if there are two lone pairs
Trigonal Bipyramidal: geometry
5 things
- There are two distinct
positions in this
geometry:
- Axial
- Equatorial
Trigonal Bipyramidal geometry
There are four
distinct
molecular
geometries in
this domain:
- Trigonal
bipyramidal (lp - 0) - Seesaw (lp - 1)
- T-shaped (lp - 2)
- Linear (lp - 3)
Octahedral geometry 6 things
3 molecular geometries:
- octahredral (lp - 0)
- square pyramidal (lp - 1)
- square planar (lp - 2)
lp = lone pair(s)
Hydrates Naming System
Some compound shave water molecules attaches as part of their strucuture - called hydrates
So, whats the naming system?
ex - CuSO4 5H2O copper(II)sulfate pentahydrate
- add the cation name (put the roman numberal if transition metal)
- Add the polyatomic anion name
- the number of H20 molecules will have greek prefixes in front of the word hydrate
periodic trends
Atomic Radius
The distance between an atom’s nucleus and its valence electrons
* Across a period - smaller
* down a group - larger
