Inorganic Chemistry Flashcards
What way can electromagnetic radiation be characterized
In terms of frequency and or wavelength
What is the order of the electromagnetic spectrum
Gamma, X-Rays, Ultraviolet, visible, infrared, radio
What units are wavelengths given in
Nano meters
What property is electromagnetic radiation said to have and why
It is said to have dual nature because it can behave as a wave or as a particle
Photon
A stream of particles that is given off when electromagnetic radiation is absorbed or emitted.
What happens when a photon is absorbed or emitted
Energy is gained or lost by electrons within the substance.
Energy associated with one mole of photons formula
E=Lhf or E=Lhc/wavelength
What happens when energy is transferred to atoms
Electrons may be promoted to higher energy levels
When is a photon emitted
When an excited electron moves from a higher energy level to a lower energy level.
This light energy emitted produces a spectrum made up of a series of lines at discrete energy levels.
What can the atomic emission spectrum be used for
Used to quantify and identify specific elements as each produces a specific absorption and emission soectra
Absorption spectroscopy
When EM radiation is directed at an atomized sample. Radiation is absorbed as electrons are promoted to higher energy levels.
Emission Spectroscopy
High temperatures are used to excite th electrons within atoms. As the electrons drop to lower energy levels photons are emitted. An emission spectrum is produced by measuring the intensity of light emitted at different wavelengths.
Different orbital shapes
S,P,D,F
Quantum number n
Indicates the main energy level for an electron and related to the size of the orbital
Angular momentum quantum number l
Determines the shape of the sub shell and have values from 0 to n-1
The magnetic quantum number m1
Determines the orientation of the orbital and can have values between -l and +l
The spin magnetic quantum number ms
Determines the direction of spin and can have a value of +1/2 or -1/2
Aufbau Principle
Electrons fill orbitals in order of increasing energy
Hunds Rule
When degenerate orbitals are available electrons fill singly keeping their spins parallel before spin pairing occurs.
Pauli Exclusion Principle
No two electrons in one atom can have the same 4 set of quantum numbers therefore no orbital can hold more than two electrons and these two electrons must have opposite spins.
Degenerate
Degenerate means of the same energy, all orbitals within each sub shell are degenerate
S block
Groups 1 and 2
P block
Groups 3-7
D block
Transition metals
What is associated with half full or full sub shells
Stability so they have higher ionisation energies
VESPR Shapes
Linear-2
Trigonal Planar-3
Tetrahedral-4
Trigonal Bipyramidal-5
Octahedral-6
Pair repulsion continuum
Non bonding/non bonding > Non bonding/bonding > bonding/bonding
Transition metal definition
Metals with incomplete d sub shells in at least one of their ions
Exceptions to the aufbau principle
Chromium and copper atoms
What happens when atoms from the first row of transition metals form ions
4s orbitals are lost first then 3d
What happens when oxidation number increases
Oxidation is taking place
What happens when there is a decrease in oxidation number
Reduction is taking place
What compounds are used as oxidising agents
Compounds containing metals with high oxidation states
What compounds are used as reducing agents
Compounds containing metals with low oxidation states
Ligands
Negative ions or molecules with non bonding pairs of electrons that they have to donate to a central metal atom forming dative covalent bonds
How can ligands be classified
Monodentate, bidentate and hexadentate
Coordination number
The amount of bonds from the central atoms to ligands
What happens when metals form complexes
Their d orbitals are no longer degenerate
How do d orbitals split
Occurs when electrons present in approaching ligands cause the electrons lying along axes to be repelled
Strong field ligands
Ligands that cause a large difference in energy between subsets of d orbitals
Weak field ligands
Ligands that cause a smaller difference in energy between subsets of d orbitals
Spectrochemical series
The series in which ligands are placed in order by their ability to split d orbitals
Colours of transition metal complexes
When light is absorbed as electrons in a lower energy d orbital are promoted to a d orbital of higher energy. If one colour of lights is absorbed the complementary colour will be present in the complex.
What light causes electrons to transition to higher energy levels
When Energy corresponding to ultraviolet(200-400nm) and visible(400-700nm) is absorbed
Heterogeneous catalysts
Catalysts that are in a different state of matter to reactants
Heterogenous catalyst can be explained as the formation of an activated complex on the surface of the reactant molecule And the adsorption of relative molecules onto active site. This is sue to the presence of unpaired d electrons. This provides alternative pathways of lower activation energy.
Homogeneous catalysts
Catalysts that are in the same state as reactants
Homogeneous catalysis can be explained in terms of changing oxidation states with the formation of intermediate complexes.
