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Chem Test 4

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Compare and Contrast ionic, and covalent bonds
see types page
What is ionic bonds?
(1)is a bond in which there is unequal sharing (2)is held together by electrostatic attraction (3)wants to be like a noble gases, by it will lose or gain electrons in order to be like a noble gas
What is a pure covalent bond?
(1)are trying to share electorn in order to be a like a noble gas (2)has a equal sharing of electrons (3) most of the time bonding is not like this bc as humans most of the time we dont want to share things equally
What is polor covalent bond?
is a covalent bond by which the bonding is spend more time near one atom than another (2) this ocurs because atoms like humans sometimes take more of things and dont share equally with one another
What is cooridnate covalent bond?
is a bond formed when both electrons or the bond are donated by the atom (2) this ocurs because atoms like humans somtimes give things to others aka electrons
How are ionic and covalent bonds similar?
all them are intramolaular attraction
What is electrostatic attratcion made up of ?
lattice energy
What keeps the ionic bonds of salts together/
lattice energy
is it hard to measure the lattic energy?
yes
What does the Born-Haber cycle show?
shows that you cant measure directly the lattice energy but u can find it indirectly
What happens to the Ionic radius if you lose electrons from Sodium?
protons stay the same, lose a e. resulting in the atom getting smaller bc there is more attractive force btwn e and p
What happens if you gain e in Sodium?
protons stay the same. resulting in the atom getting bigger bc you have less attractive force btwn e and p
What are bonding pairs?
electrons that bond
What lone pairs?
non-bonding pairs
How do you find the lattice engeriges from the Borrn-Haber cycle? (5)
(1)sublimation of sodium (2)dissocation of chlorine (3)Ionization of sodium (4)Formation of chloride ion (5)formation of NaCL from ions (6)list the five steps and add them up using hess's law
What is the ionic radius?
is the measure of the size of the spherical region around the nucleus of an ion with in the electrons are most likely to be found
What is isoelectronic?
refers to the different species having the same number and configuartion of electrons
Describe what happens to the ionic radius in the periodic table
In general, across the period the cations decrease in radius. when you reach the anions, there is an abrupt increase in the radius and then the radus will decrease again
Why does the ionic radi increase down any column?
bc of the addition of electron shells
What is ocet rule?
the tendecny for atoms in molecules to have eight electrons in their valecne shell
What is the max amount of bonds a atoms can have?
3
What is electronegativity?
is measure of the ability of an atom in a molecule to draw bodning electrons to itself
How did Muileken contrubite to chemistry?
by coming up with a formuala for electronegavitiy
X= I.E -E.A. /2

x=electronegativty
I.E= ionization energy
E.A.=electron affinity
What are the general trends of electronegativty for the periodic table? (3)
the elecronegativty increases from left to right (2)decreases from top to bottom (3) metals have the least electronegative elements and non-metals have the most electronegative
What is the resonance disrcitipion?
is the electron structure of a molecule having a delocalized bond by writing all posssible eletron dot-formulas
Give some ex of execptions to the Octet rule?(3)
(1)NO3 (2)PF5 (3)BF3
What is the formal charge of an atom? Give two rules to apply to it (3)
(1)formal charge= valence eletrons on free atom-1/2(number of electrons in the bond-number of lone pair electrons (2)half of the electrons of a bond are assigned to each atom in the bond (3)both electrons of a lone pair are assigned to the atom to which the pair belongs
What are two rules for writing Lewis Formulas?
(1)whenever you write several lewis formuals for a molecule, chose the one having the lowest maginitude of formal charges (2)when two proposed Lewis formualas for molecule have the same magnitude of formal charges, chose one having the negatvie formal charge on the more electronegative atom
How has the tetrahderon played a important role in history?
(1)the tetrahadron is a balanced and one top is always sticking up (2)This, helped the underdogs in warfare. For instance, during the Roman times, the tetrahedron was called a cowtrap. The cowtrap had pointy edges and was used to take down the horses (3)In addition, the tetrahedron is even used today during World War II, Korean, and Vietinman war (dipped it in urine and feces to causes the troops to step on it and get a infection)How
What are the angles in the triganal bipyramidal?
10 degrees top from bottom
What are the angles of octahedral?
look the same from each direction and 90 from each other
For shape, how do double act?
as a single bond
A (1) tends to require more space than bonding pair causing more atoms to be squashed together
lone pair
Make a chart to tell how to find the electron and molecular geomerty
see notes
What is a dipole moment?
is a quantitative measure of the degree of charge seperation in a molecule
How do you find the dipole moment?
particle's charge and particle
What is the relationship btwn molecular geometry and the dipole moment?
see chart on page 387 or in notes
What does a equal dipole moment?
means each atoms is bein pulled equally
T or F
No matter what shape Ax have the same electronegativity
Ax
How do u firgue out the dipole moment?
(1)determine if there is a dipole moment by findng the differ in eletronegativty charges. if there eletronegavity is the same there is no dipole moment and it equals zero and if there is a differ = it has a dipole moment (2)determine if the differ cancels out. if it does =zero and if it doesnt=can be nonzero
When is there no dipole moment?
if they have the same eletronegavity
Does the dipole moment depend on shape?
no
What is the Basic bond theory? (5)
(1)where two atoms overlap bonds ocur and where e ocupy some space (2)if e are not in some space, then they are pulling apart, thus they want the best overlap (3)more overlap=stronger bond, weaker bond= less overlap (4)thus, the closer e are and the more they overlap, the sronger the bond (5)atoms always have a max of two e in there orbital
If two atoms overlap a lot, it is a (1) bond
strong
if two atoms barely overlap, it is a (1)bond
weak
What are the best types of bonds?
have the most blend os s and p (2) s with its flexibity and p w its longness
What are hybrid orbitals?
are orbitals used to describe bonding that are obtained by taking comboinations of atomic orbitals of the isolated atoms
The number of hybrid orbitals is always equals the (2)
number of atomic orbitals being used
(1) is always equal to the number of atomic orbitals being used
the number of hybrid orbitals
What is the relationship btwn the hybrid orbitals and their geometric arrangement?
sp = linear = 2
sp2= triganal planar =3
sp3 = tetrahedral = 4
sp3d = trigonal bipyramidal =5
sp3d2 = octahedral=6
what are the five steps for obtaining the bonding desricption?
(1)Find the lewis eletron dot formula (2)Find the VSEPR and find the electron pairs (3)find the type of hybrid orbitals required (4)assign valence electrons to the hybrid orbitals (5)form bonds to this atom by overlapping singly occupied orbitals of other atoms w singly occupied hybrid orbitals of this atom
What is a sigma bond?
has a cylindrical shape about the bond axis
What is a pi bond?
has an electron distrubition above and below the bond axis
How are sigma bonds formed?
(1)the overlap of two s orbitals (2)by the overlap of two p orbitals along their axis
How is a pi bond formed?
when two p orbitals overlap sidways
When two p orbitals overlap sideways a (1) is formed
pi bond
When two s orbitals overlap a (1) is formed
sigma bond
When two p orbitals overlap by their axis a (1) is formed
pi bond
What is give the pros and cons of p and s orbitals?
p= orbitals bind in only one direction and are longer

s =obritals bind in all directions making them flexible
pi bond is usally w (1)
p orbitals
a single bond =
a sigma bond
What is the main differ between the valence bond theory and teh molecular orbital theory?
(1) the valence bond theory talks about atomic orbitals overlapping (2)molecular orbital theory is the theory of eletronic strucutre of molecules in terms of molecualar orbitals, which may spread over several atoms or the entire molecule
What is the differ btwn antibonding and bonding? (2)
There are two types of molecualr orbitals, bonding and anitbonding. Bonding orbials are that are concentrated in regions btwn nuclei. The bonding orbitals have lots of overlap and high energy. (2) Unlike the antibonding orbitals. The anitbonidng orbitals are molecualar orbitals having zero values in the region btwn two nuclie. There is no bonding and has low energy
What are the anitbonding orbitals? (2)
(1)The anitbonidng orbitals are molecualar orbitals having zero values in the region btwn two nuclie. (2)There is no bonding and has low energy
Whar is bonding orbitals?
(1)Bonding orbials are that are concentrated in regions btwn nuclei. (2)The bonding orbitals have lots of overlap and high energy.
What are two factors determine the strength of the interatction btwn two atomic obritals?
(1)the energy difference btwn the interacting orbitals (2)the maganatidue of their overlap
For the interaction of two orbtials to be strong the energies of the two orbitals must be (1) and (2)
(1)aprox equal (2)have large overlap

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