Mini test 2 Flashcards
Chemical kinetics
The study of the rates of chemical reactions and the factors that influence reaction rates
Reaction rate
& factors that affect it
A measure how rapidly a reaction occurs related to the rates of change in the concentration of reactants and products overtime
- physical states of reactants
- concentration
- temp
- catalysts
Rate law
K[A^m[B]^n
Rate order
Indicates how a certain variable effects the rate of reaction and how fast it can happen
Zero order
The rate is independent of the concentration of a particular reactant
Pseudo first order
Have one reactant much more concentrated than the other so that the smaller reactant doesn’t matter to the overall reaction rate creating a first order reaction
Half life
How much time it would take to cut the initial concentration in half
Collison theory
Explains how chemical reactions occur and why they happen at different rates
Molecules should collide
Orientation of molecules ( addition of catalyst)
Have enough energy
Activation energy
The minimum amount of energy that must be produced video to a chemical reaction to initiate the process of transferring products to reactants
Use the arrihenius equation
Reaction mechanism
Shows the step-by-step process to get the overall net reaction
Elementary reaction
Steps written as true single steps
Intermediate
Create in the first step used up in the second
Catalyst
Present at the beginning present at the end
Speeds up the overall reaction by orienting the molecules correctly and lowers the activation energy
Homogenous catalyst: occurs in the same phase as the reacting molecules
Heterogeneous: exist in a different phase from the reacting molecules
Rate determining step
The mechanism with the slowest step
This is what determines the rate law (can be manipulated to exclude intermediates if involved in the second or other than the first step)
**Always assume equilibrium in the fast steps
Radionuclide
Atoms with an unstable nucleus spontaneously emit particles and electromagnetic radiation (gamma rays/photons)
Does this to reach a more stable state (one with less energy=less protons)
Radioactivity is independent of temp pressure andphysical state
alpha decay
large nucleotide
becomes more stable by becoming smaller, emitting an alpha particle (He)
In a large nucleotide, it will either undergo alpha decay or spontaneous fission
beta decay
too many neutrons in the neutron to proton ratio so emits a beta particle (electron)
**neutron is made up of proton and electron so beta emission is just splitting that
gamma radiation
the neutron is in an excited state so it emits energy in the form of light
electron capture
too many protons so forms a neutron from a proton and an electron
positron emission
too many protons so it splits into a neutron and a positron (electron with a positive charge)
binding energy
the energy required to separate nucleons (just one nucleon)
**nuclear fusion
one of two ways to release binding energy: reaction in which two light nuclei join together to form a heavier one
Usually from a lighter atom wanting stability
opposite of fission
products are more stable than before
nuclear fission
one of two ways to release binding energy: reaction in which a heavy nucleus splits into 2 lighter ones
sometimes this can cause a spontaneous chain reaction, but has to be at its critical mass in order to do so
opposite of fusion
products are more stable
chain reaction
neutrons from the fission reaction split apart initiating more fission reactions
only possible with the critical mass, which is the minimum quantity of fissionable material needed to sustain a chain reaction
neutron activation
atomic nuclei absorb free neutrons, creating unstable isotopes, thus radioactive atoms
disintegration reaction
any process in which an atomic nucleus breaks up spontaneously into 2 or more fragments in a radioactive decay process or breaks up as a result of a collision with a high-energy particle or nuclear fragment
A=kN (A is ALWAYS in Bq)
***one disintegration per atom
radioactive decay
the breaking up of an unstable nucleotide into a more stable state
Includes alpha, beta, gamma, EC, and PC
independent of pressure temperature and physical state (due to how far
