collision theory?

Question

a chemical reaction rate doubles when the concentration of one reactant is doubled. please explain this in terms of collision theory.

Answer 1

Collision theory is a theory, proposed by Max Trautz and William Lewis in 1916 that qualitatively explains how chemical reactions occur and why reaction rates differ for different reactions.[1] It assumes that for a reaction to occur the reactant particles must collide, but only a certain fraction of the total collisions, the effective collisions, cause the transformation of reactant molecules into products. This is due to the fact that only a fraction of the molecules have sufficient energy and the right orientation at the moment of impact to break the existing bonds and form new bonds. The minimal amount of energy needed so that the molecule is transformed is called activation energy. Collision theory is closely related to chemical kinetics


Rate constant
The rate constant for a bimolecular gas phase reaction, as predicted by collision theory is:


K (T) = Zp exp ( ea/rt)
.

Z is the collision frequency.[2]
is the steric factor.[3]
E a is the activation energy of the reaction.
T is the temperature.
R i s gas constant.
And the collision frequency is:




Z = N AQ AB /8k bT/AB

NA is Avogadro's number
σAB is the reaction cross section
kB is Boltzmann constant
μaB is the reduced mass of the reactants


Qualitative overview


Fundamentally collision theory is based on kinetic theory and therefore it can only be applied strictly to ideal gases, otherwise approximations are used. Qualitatively, it assumes that the molecules of the reactants are rigid, uncharged spheres that physically collide prior to reacting. Moreover, it postulates that the majority of collisions do not lead to a reaction, but only those in which the colliding species have:

A kinetic energy greater than a certain minimum, called the activation energy, Ea
The correct spatial orientation (steric factor) with respect to each other.
These collisions which lead to reaction are called effective collisions. The reaction rate, may be defined as the number of effective collisions per unit time.

According to collision theory, two significant factors determine reaction rates:

Concentration: Increase in concentration of reactants increases the collision frequency between the reactants. Thus the effective collision frequency also increases.
Temperature: The kinetic energy of particles follows the Maxwell-Boltzmann distribution. An increase in temperature not only increases the average speed of the reactant particles and the number of collisions, but also the fraction of particles having kinetic energy higher than the activation energy. Thus, the effective collision frequency increases.
If a heterogeneous reaction takes place, then the surface area of the solid is also important: the more reactive centers exposed on the surface (due to the porosity of the solid and how finely divided it is), the more collisions with reacting molecules.

Answer 2

Collision Theory

Answer 3

concentration will enhance the type of debris in the answer and hence makes a collision, and as a effect a reaction, more beneficial in all probability. The power in contact in the collisions is in trouble-free terms effected through temperature enhance. that is because increasing the temperature will enhance the quantity each and each and every particle vibrates because it leads to an enhance in kinetic power.

Answer 4

Two objects collide, k? now, a reaction requires two things: correct reaction geometry and sufficient kinetic energy. If either or both of these two pre-requisites are not met, then the collision does not lead to the formation of products and the reactants simply "bounce" off each other.

double the concentration of one reactant, then you double its mass. Kinetic energy increases with mass, thus doubling the chances of reaction.