Collision Theory and Rate Equation Flashcards
Factors Affecting Reaction Rate
Conc, Temp, catalysts and surface area
Chemical Kinetics def
Study of rate at which chemical reactions occur, the factors effecting rate and mechanisms
Relationship between concentration and rate
higher conc = faster rate
Relationship between temp and rate
Higher temp = faster rate
Relationship between catalysis and reaction rate
Catalyst presence = faster reaction rate
Relationships between surface area and reaction rate
Increased surface area = faster rate
What types of collisons need to occur for reactions
Effective. Bonds broken and formed
Factors effecting an effective reaction
Molecular Orientation, Collision Energy, Collision Frequency
Molecular Orientation Outline
Atoms in molecules need to be positioned so that when collided transfer of atom(s) can occur. Atoms joining another molecule must be facing that molecule
Energy Collisions Outline
In an effective collision molecules must collide with an energy higher then the force of repulsion between molecules due to electron clouds
Frequency of collisions outline
The higher the frequency of collisions is the higher the possibility of an effective collison
Rate of Reaction Def
Change in conc of reactant/product per unit time. Increase in rate is faster = higher concentration reduced/produced per set time. Unit: mol/L/s. Rate of reaction is negative for reactants and positive for products
Rate Laws outline
Define dependence rate of reactions have on concentrationchange. Can only be inferred experimentally
Differential Rate Law
Relationship between reaction rate and reactants conc. Rate is proportional to reactant conc
Integrated Rate Law
Relationship between reactants conc and time
How is reaction rate calculated when presented graph of time (x) vs reactant conc
Create tangent line to line of points at time/conc given. Find slope of tangent line. Units: units of conce/units of time
What other piece of info must be disclosed with rate
Temperature. Rate at a given time is temperature dependent
Rate Law Equation
Rate = k [Reactant Conc A]^x [Reactant Conc B]^y
Order of Reaction Def
Mathematical description of relationship between reaction rate and reactant conc(s). Order of total reaction = sum of Partial orders ( individual reactants orders). Determined by experiment
0 order reaction relationship between concentration and rate
No change in rate regardless of concentration. Rat eis constant. B is independent of C
1st order reaction relationship between rate and conc
As conc doubles, rate doubles. 2B =2C
2nd order reaction relationship between rate and cons
As conc doubles, rate quadruples. 2^2B = 2C
Pseudo 1st Order Reaction Outline
Reaction that’s not naturally 1st order but is made 1st order by intentionally altering the conc. of reactant(s). Eg a reactant being added in excess (combines with constant)
Knowledge of reaction order and drug dosage
Balancing potency between effectiveness and toxicity. Reaction rate increases as conc does. To decrease damage done, decrease dosage conc
Half Life Def
Time required for drug conc to decrease by 50% of previous conc. Allows us to admin correct dosages balancing pharmalogical effect and toxicity
