Ad
related to: forward and backward reactions definition ap bio test review book free pdf
Search results
Results From The WOW.Com Content Network
Equality of forward and backward reaction rates, however, is a necessary condition for chemical equilibrium, though it is not sufficient to explain why equilibrium occurs. Despite the limitations of this derivation, the equilibrium constant for a reaction is indeed a constant, independent of the activities of the various species involved ...
In physical chemistry, the Arrhenius equation is a formula for the temperature dependence of reaction rates.The equation was proposed by Svante Arrhenius in 1889, based on the work of Dutch chemist Jacobus Henricus van 't Hoff who had noted in 1884 that the Van 't Hoff equation for the temperature dependence of equilibrium constants suggests such a formula for the rates of both forward and ...
where k f is the rate constant for the forward reaction and k b is the rate constant for the backward reaction and the square brackets, […], denote concentration. If only A is present at the beginning, time t = 0 , with a concentration [A] 0 , the sum of the two concentrations, [A] t and [B] t , at time t , will be equal to [A] 0 .
Guldberg and Waage also recognized that chemical equilibrium is a dynamic process in which rates of reaction for the forward and backward reactions must be equal at chemical equilibrium. In order to derive the expression of the equilibrium constant appealing to kinetics, the expression of the rate equation must be used.
Chemical equilibrium is a dynamic state in which forward and backward reactions proceed at such rates that the macroscopic composition of the mixture is constant. Thus, equilibrium sign ⇌ symbolizes the fact that reactions occur in both forward ⇀ {\displaystyle \rightharpoonup } and backward ↽ {\displaystyle \leftharpoondown } directions.
The magnitude of the equilibrium constant depends on the Gibbs free energy change for the reaction. [2] So, when the free energy change is large (more than about 30 kJ mol −1), the equilibrium constant is large (log K > 3) and the concentrations of the reactants at equilibrium are very small. Such a reaction is sometimes considered to be an ...
where: k 1 is the rate coefficient for the reaction that consumes A and B; k −1 is the rate coefficient for the backwards reaction, which consumes P and Q and produces A and B. The constants k 1 and k −1 are related to the equilibrium coefficient for the reaction (K) by the following relationship (set v =0 in balance):
The forward and reverse reactions are competing with each other and differ in reaction rates. These rates depend on the concentration and therefore change with the time of the reaction: the reverse rate gradually increases and becomes equal to the rate of the forward reaction, establishing the so-called chemical equilibrium.