Chemical Principles Åk 1 Flashcards
Var på y-axeln börjar kurvan på en s orbital och hur ser kurvan ut beroende på noderna? Hur ser Ψ, Ψ^2 och 4pir^2 Ψ^2 kurva ut?
Den börjar högre upp på y-axeln. Först ritar man kurvan som vanligt med Wavefunction Ψ och alla noder så ifall n=3 ska den ha 3 kurvor. Sedan blir Ψ^2 och alla kurvor som passerar under x-axeln blir positiva och alla 3 kurvor är på den positiva axeln. Sedan börjar man med den minsta kurvan, näst minst och störts. Så ser kurvan då ut.
Var på y-axeln börjar en p orbital och hur ser kurvan ut? Hur ser Ψ, Ψ^2 och 4pir^2 Ψ^2 kurva ut? Hur ser kurvan ut beroende på noderna?
Den börjar vid origo. Först ritar man kurvan som vanligt med Wavefunction Ψ och alla noder så ifall n=3 ska den ha 2 kurvor. Sedan blir Ψ^2 och alla kurvor som passerar under x-axeln blir positiva och alla 2 kurvor är på den positiva axeln. Sedan börjar man med den minsta kurvan, näst minst och störts. När man sen skriver 4pir^2 Ψ^2 så börjar den vid origo.
Kurvorna är lika med mängden noder-1
Vad indikerar MO theory och hur ser dess diagram ut?
MO Theory = Molecular orbital diagram. Visar hur de olika elektronerna ligger i sigma och pi bindningarna när elektroner binder ihop sig. alla valenselektroner är dilokaliserade runt molekylen.
Man börjar med sigma sen sigma.
Sedan: pi, sigma sen pi,sigma*.
Hur beräknar man Bond order?
((Number if electrons in bonding orbitals- number of electrons in anti bonding orbital)/2).
Du räknar antalet elektroner som är bonding så i 2s^2 är det 2 elektroner, sedan subtraherar du med mängden elektroner som är i antibonding orbitalen och dividerar sedan med 2.
What is a Lewis structure and how do you Apply it to a molecule
Lewis structure tells you how where and how many electrons are located around an atom and how they are bonded in a molecule.
You start by counting the valance electrons on each of the atoms and then transfer the cations electrons to the anion and draw the bond. The anion is the atom who’s more electronegative
What is lattice energy?
The difference in energy between the ions of a compound separated as a gas and packed together in a solid.
Whats a lone pair?
A pair of valance electrons had doesnt participate in bonding (anti bonding)
What’s the octet rule?
Atoms in covalent bonds go as far as possible to complete their shells with electrons by sharing the electrons
What’s a central and terminal atom?
Central atom: bonded to at least two other atoms and is the center of the molecule, it’s written first in the molecules name.
Terminal atom: an atom bonded to only one other atom
How are acids compound name written?
An H is written first on the compound
What does resonance mean? How is the molecule written according to the energy?
Blending of Lewis structures of a molecule. Occurs when there’s a double bond that rotates all around the the molecule because of their symmetry and final charge.
The chosen resonance structure always contributes the most to the lowest energy. Resonance structures with the same structures (symmetrical) contribute with equal energy to the resonance structure
What does formal charge mean and how do you apply it?
What is it’s equation?
What is said about the Lewis structures formal charge?
Formal charge equation: valence electrons - (lone pairs + bonding electrons/2)
The formal charge is the charge the of an atom it would have if the bonding were covalent.
The arrangement of a molecule with the lowest formal charge results in the lowest energy.
What is a dipole-dipole bond? And what does electronegativity has to do with it?
a dipole dipole bond is when two or more atoms share the the electrons but one is more electronegative than the other which makes easier for it to pull the other electrons from the atoms toward it.
The greater the electronegative the atom is the greater it’s pull on the other atom is and the harder it is for the atom to loose its electrons.
What does low- and high ionizing energy indicate?
Low ionizing energy = low electronegative atom, takes little energy to remove electrons from it.
High ionizing energy = high electronegative atom, takes a lot of energy to remove electrons from it.
Name a weak and strong acid. How do their balanced equation look?
Strong acid: H2SO4 (svavelsyra, you use a normal arrow because it proteolyses the whole way ->)
weak acid: HAc (acetic acid) you use equilibrium arrows
What does bond strength mean and how do you calculate it?
It’s the strength of a bond between 2 atoms. It’s measured by the energy required to separate the bonds.
You draw the molecule and add together all the bonds energies you see which results in the molecules strength.
Namn the 4 strongest Bonds from strongest to weakest
Coulombic attraction,dipole-dipole, hydrogen bonds and London dispersion.
What’s the VSEPR model?
By it’s 4 rules it explains in what angles the atoms in the molecule are bonded.
What’s the 1 rule of the VSEPR model?
Regions with high electron concentration (lone pairs on the central atom and bonds) repel each other. The repulsion is minimized by moving these regions as far away from each other as possible.
What arrangement gives the electron arrangement?
The most distant way the electrons/atoms lie to each other in a molecule
What’s the 2 rule of the VSEPR model?
A multiple bond is grated as a single region of high electron concentration. Ex a double bond repel other atoms/lone pairs as one unit
What’s the 3 rule of the VSEPR model?
All regions of high electron concentration, lone pair and bonds, are included in the description of the electron arrangement but only the positions of the atoms are considered when identifying the shape of the molecule
What’s the 4 rule of the VSEPR model?
Strengths of repulsion:
Lone pair-lone pair > lone pair-atom> atom-atom
What’s a polar molecule?
A molecule with dipole-dipole moments.
What’s a non polar molecule?
A molecule with zero dipole-dipole moments
What’s the VB (valence bond) theory?
The description of covalent bonding in terms of atomic orbitals sigma and pi.
What sigma and pi bond indicates a single, double and triple bond?
Single bond: 1 sigma bond
Double bond: 1 sigma and 1 pi bond
Triple bond: 1 sigma and 2 pi bonds
What do the sigma and pi boxes look like? How many electrons fit in them
Sigma = 1 Box that can fit 2 electrons Pi= 2 boxes that can fit 4 electrons
Whats a bonding and antibonding orbital?
Bonding orbital = doesnt have * marked on it and it participates in the bonding with the atoms
Antibonding orbital= has an * marked on it, doesn’t participate in the bonding between atoms in a molecule
*What does isothermal mean? And what happens during it?
Constant temperature.
What does diffusion mean?
One substance goes through another one
What does effusion mean?
The escape of gas through a small hole towards a region with lower pressure
Name the three different phases.
Solid liquid gas (vapor)