Lecture 16 Flashcards
Chemical Kinetics and Reaction Rates (19 cards)
What is chemical kinetics?
-How reactions happen
-Theories of how reactions occur
-Important for understanding and predicting reactions
reaction rates and factors that control them
-Important for real life synthesis, decomposition and atmosphere chemistry
To react, particles must?
-collide
-break bonds
-form bonds
Fewer collisions results in a (faster/slower) reaction rate.
slower
(Less/More) particles above the Ea activation energy leads to more successful reactions
More
An increase in temperature will (increase/decrease) the reaction rate.
Increase
An increase in concentration will (increase/decrease) the reaction rate
Increase in reactants, increase in reaction rate
What are 3 things that can increase collisions (aka reaction rate)?
- temp
- concentration
- changing the orientation of your reactants
Do collisions always result in a reaction?
No
Are molecules that collide held together longer in gas phase or solution?
Solution because they are less likely to change orientation as gases do.
What is a rate law?
The relationship between rate and reactant concentration [A]
it is “m+n”th order
what is k?
the rate constant, a constant number with units
rate = R[A]^m[B]^n
Is m and n the coefficient of the reactant/product?
NO
other notes:
-must be determined experimentally
-usually integers but not always
What does it mean when a reactant/product has an order of 0?
The rate of the reactant/product is not affected by the rate of other reactant/products in the reaction.
What is the overall order of k[A][B]^2
3rd order
what is k?
proportionality constant - a number with units
that relates rate to concentration
rate law: k[A]
What is the order of k?
first order
What are the units for the 6th order of k?
1/(m^5*s) = M^-5s^-1
The units of k is M^-13s^-1. What is the order of the reactant?
14th order
For first order process rate = k[A], when [A] doubles, —
rate doubles
