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