How Does Particle Size Affect Reaction Rate

Factors That Affect Chemical Reaction Rate — Factors That Affect Reaction Rate

Several factors bear upon reaction charge per unit. A chemic reaction only occurs if reactant particles collide with each other successfully. Anything which increases the likelihood of successful particle collisions increases reaction rate.

Using these factors to control the rate of a chemical reaction is important for many chemic processes. For example, slowing a highly exothermic reaction may prevent an explosion. Speeding the rate of a glow stick reaction makes its light glow brighter. Here is a list of factors that affect reaction rate, an explanation of why they work, and a expect at the limitations of increasing charge per unit.

Summary of Factors That Affect Reaction Rate

Gene	Affect on Reaction Rate
Temperature	Increasing temperature increases reaction charge per unit (upward to a point)
Pressure	Increasing force per unit area of gases increases reaction rate
Concentration	Increasing the corporeality of reactants in a solution increases reaction rate
Catalysts	Catalyst presence increases reaction rate
Particle Size	Decreasing particle size or increasing surface area increases rate of reaction
Physical State	Reactants in the same state of matter react more readily than those in different phases. Mixing helps improve reaction rate.
Light	Some reactions become their activation free energy from lite, increasing the rate of the chemical reaction.
Nature of Reactants	Some types of reactions are inherently faster than others.

A Closer Look at the Factors

Temperature

Temperature is often the factor that has the greatest upshot on reaction rate. Increasing temperature gives particles kinetic energy so they bounce effectually more than quickly and are more likely to combine. More than chiefly, the added energy is more likely to meet the activation energy requirement for the reaction. In contrast, lowering the temperature makes molecules slower and less likely to react.

The rate of many chemicals reactions doubles for each 10 °C increase in temperature. The "rule" applies to well-nigh, but not all reactions. For case, many biochemical reaction rates double with much smaller temperature increases. Also, there is an upper temperature limit above which a reaction volition boring or terminate.

Pressure

Increasing pressure forces reactant particles closer together, increasing their interaction and the rate of reaction. As you might expect, pressure affects gases significantly more than liquids or solids.

Concentration

Increasing the concentration of liquid and gaseous reactants increases the number of collisions betwixt particles and thus increases the reaction rate.

Utilise of a Catalyst

Catalysts or enzymes lower the activation energy of a chemical reaction. Since it'southward easier for the reaction to occur, information technology's faster.

Catalyst and Activation Energy — A catalyst speeds upwards a chemic reaction by offering a different pathway to complete the reaction that has a lower activation free energy.

Catalysts increase the frequency of collisions between reactants, alter molecular orientation, reduce intermolecular bonding within reactants, or donate electron density to reactants. The presence of a catalyst doesn't change a chemical reaction, but it does help it reach equilibrium more quickly.

In contrast, some substances decrease the rate of a chemical reaction. These inhibitors may compete for a reactant, change reactant orientation, or modify electron density of chemical bond formation.

Particle Size – Surface area

Smaller particle sizes and increased surface area maximize opportunities for reactants to collide. Burdensome solids into powders increases expanse. For instance, a chunk of magnesium metal oxidizes in air, but powdered magnesium oxidizes then chop-chop information technology tin spontaneously ignite.

Physical State of Reactants

The physical state of the reactants (solid, liquid, gas) affects the rate of reaction. Liquid and gaseous reactant in the same phase tend to react quickly considering thermal motion brings them together. The speed of a reaction is express by the area of the interface when reactants are in different phases. Here, shaking and mixing tin speed the rate of the reaction by bringing reactants together.

Absorption of Light

Calorie-free provides the activation free energy needed for some reactions. For these reactions, increasing the amount of light increases the charge per unit of reaction. Photosynthesis is a good example of a reaction affected by lite.

Nature of the Reactants

The types of chemic bonds in the reactants influence how quickly reactions occur. For example, acid-base and ion-exchange reactions tend to be fast reactions. Reactions involving large molecules tend to exist slower. Sometimes information technology's possible to increment the rate of a reaction past choosing different compounds to yield the desired product. For example, in a substitution reaction, y'all'll become a faster reaction using a soluble salt than an insoluble one because the soluble salt volition dissolve into smaller particles.

Limitations to Speeding the Rate of a Reaction

There is a limit regarding how much a factor can increase the rate of a chemic reaction. For instance, increasing temperature speeds up a reaction, only above a sure temperature the reactants may denature. Calculation a catalyst speeds a reaction, but adding more of information technology won't cause a further rate increase.

References

Atkins P.; de Paula J. (2006). Physical Chemical science (eighth ed.) Due west.H. Freeman. ISBN 0-7167-8759-eight.
Laidler, K. J. (1987). Chemical Kinetics (tertiary ed.). Harper and Row. ISBN 0-06-043862-two.
Steinfeld, J. I.; Francisco, J. S.; Hase, Due west. 50. (1999). Chemical Kinetics and Dynamics (2nd ed.). Prentice-Hall. ISBN 0-13-737123-3.