Chapter 13 Flashcards
chemical kinetics
study of reaction rates during a chemical reaction
reaction rates
how rapidly a reaction occurs
what affects reaction rate
physical state of reactants, concentration of reactants, temperature, presence of a catalyst
what happens to the reactants concentration as the products concentration increases?
the reactants concentration decreases
average rate
change in concentration of reactant or product over a specific time interval
what do you do to find the rate at one moment?
use tangent curve
what do reaction rates depend on?
concentration
what happens to the reaction rate as the concentration decreases?
the reaction rate decreases
reaction order
experimentally determined number defining the dependence of the reaction rate on the concentration of a reactant
rate law
equation that defines the relationship between reactant concentrations and the rate of the reaction
instantaneous rate
rate of a reaction at a particular time after its begun
when do the most rapid changes in concentration happen?
early in the reaction
overall reaction order
sum of the exponents of the concentration terms in the rate law
does the rate constant depend of the concentration of the reactants?
nope
what affects rate constants?
temperature and the presence of a catalyst
integrated rate law
change in concentration of a reactant with time
half-life
time interval during which the concentration of a reactant decreases by half in the course of a chemical reaction
how does a higher reaction rate affect the half-life?
means a shorter half-life
how do you express rate of change?
as a positive value
Pseudo-first-order
all reactants but one are present at such high concentrations that they don’t decrease significantly during the reaction
what controls the reaction rate in a pseudo-first-order reaction?
concentration of the limiting reactant
Zero-order
rate of reaction is independent of concentration
activation energy
minimum energy molecules needed to react when they collide
activated complex
short-lived species formed in a chemical reaction
transition state
high-energy state between reactants and products in a chemical reaction
