chemistry online courses

basic chemistry concepts free tutorial

2011-06-06T17:09:00.000+02:00

Alot of basic concepts of chemistry has built on Standard periodic table of the chemical elements ,and due to the big variety of propertities of elements that has been found ,scientsists forworded to identifing basic concepts on basis of make the study of periodic table more closly to both whome study or searching all over branches of chemistry ,basic concepts of chemistry almost do not change from any branch of chemistry to another,but sometimes organic chemistry utilizing special concepts and different basics than General chemistry or Physical chemistry at all,
Here are approaches to satisfying and categorizing a handfull of properties of elements as a basic chemistry concepts:
* Apparatus : Bunsen burner — Calorimeter — Colorimeter — Burette — Thermometer
* Atomic structure : Atom — Ion — Electron — Proton — Neutron — Atomic orbital — Molecular orbital — Chemical element — Valence — Atomic nucleus — Isotope
* Bonding : Chemical bond — Ionic bond — Covalent bond — Metallic bond — Hydrogen bond — Intermolecular force — Dipole — Electron pair — Unpaired electron
* Chemical reaction — Chemical formula — Structural formula — Mole — Stoichiometry — Chemical nomenclature — Chemical equilibrium — Reversible reaction — Electrophile — Nucleophile — Redox
* Chemical techniques : Titration — Distillation — Chromatography — Reflux — Buffer solution — Filtration — Hydrolysis — Condensation reaction
* Important Chemical substances: Matter — Water — Ammonia — Benzene — Phenol
* Mixtures and Solutions: Concentration — Vapour pressure — Raoult's law — Partial pressure — solvation
* Periodic table : Periodicity — Group 1 elements — Group 2 elements — Transition metal — Group 5 elements — Group 6 elements — Halogen — Noble gas — s block — d block — p block — f block
* Properties : pH — electronegativity
* Structure : Gas — Liquid — Molecule — Solid — Isomer — Allotropy — Crystal — Complex (chemistry) — Ligand — Chemical compound — Stereochemistry

Basic chemistry concepts based on branch of chemistry

* Analytical chemistry :
o Electrochemistry : Electrochemical cell — Oxidation — Reduction — Electrode potential — Oxidation number — Electrolysis — Electrolytic cell — Electrolyte — Nernst equation
o Spectroscopy : atomic absorption spectroscopy — Auger electron spectroscopy — electromagnetic spectroscopy — fluorescence spectroscopy — infrared spectroscopy — mass spectrometer — Mössbauer spectroscopy — nuclear magnetic resonance — neutron activation analysis — Raman spectroscopy — UV/Vis spectrophotometry — X-ray photoelectron spectroscopy —
* Inorganic chemistry : Alkali — Acid — Base — Metals — Nonmetals — Salt — pH
o Solid state chemistry
* Organic chemistry : Functional group — Hydrocarbon — Alkane — Alkene — Halogenoalkane - Alcohol — Ether — Aldehyde — Ketone - Carboxylic acid — Ester — Alicyclic compound — Amine — Amide — Amino acid — Polymer — Polymerization — Organic nomenclature — Arene — Phenol — Peptide
o Stereochemistry : Optical isomerism — Chirality
* Physical chemistry :
o Kinetics: Catalyst — Enzyme — Arrhenius equation
o Thermochemistry : Enthalpy — Activation energy — Entropy
o Computational chemistry : Molecular modeling — Molecular dynamics — Molecular mechanics — Quantum methods — Combinatorial chemistry — Cheminformatics — Bioinformatics
o Quantum chemistry : Slater determinant - Self-consistent field — Hartree-Fock — Moller-Plesset - Electron correlation - Semiempirical methods
* Biochemistry : Protein — Carbohydrate — Fat — Nucleic Acid

Study of basic chemistry concepts leading to remember those Scientists who build the chemistry basics
Some famous chemists.
* Marie Curie
* John Dalton
* Humphry Davy
* Eleuthère Irénée du Pont
* George Eastman
* Michael Faraday
* Dmitriy Mendeleyev
* Alfred Nobel
* Wilhelm Ostwald
* Louis Pasteur
* Linus Pauling
* Joseph Priestley
* Karl Ziegler
Basic chemistry concepts of Functional groups and compounds and international synonamous:
* alkane
* alloy
* biochemistry (topic)
* CAS number (by chemical compound)
* elements (by atomic number)
* hazardous substance
* publications
* inorganic compound
o compound (by element)
* organic compound
cf (NFPA 704, IARC (carcinogen))
but remember again when facing basic term or concept in chemistry;the chemistry has broad basic concepts and basic terms but different meaning to the same concept or term is based on properties of the compounds that being studied.

Collision Theory in Chemical Kinetics

2011-04-02T16:05:00.000+02:00

The collision theory describes reaction rates changes and other factors of collision theory that depending and /or effecting or affected by Reaction rates. factors of collision theory tells us whether a collision will result in a reaction - in particular, the energy of the collision, and whether the molecules of the other hit the right path (the orientation of the collision).

factors of collision theory that affecting the rate of reaction (temperature, concentration, etc.) are discussed on separately . You can get from these rates through the Following List:

conc,Temperature,Pressure Factors in collision theory

2011-04-02T16:04:00.000+02:00

Reactions happen, no matter what. Chemicals are always combining or breaking down. The reactions happen over and over but not always at the same speed. A few things affect the overall speed of the reaction and the number of collisions that can occur.

Concentration: If there is more of a substance in a system, there is a greater chance that molecules will collide and speed up the rate of the reaction. If there is less of something, there will be fewer collisions and the reaction will probably happen at a slower speed.

Temperature: When you raise the temperature of a system, the molecules bounce around a lot more (because they have more energy). When they bounce around more, they are more likely to collide. That fact means they are also more likely to combine. When you lower the temperature, the molecules are slower and collide less. That temperature drop lowers the rate of the reaction.

Pressure: Pressure affects the rate of reaction, especially when you look at gases. When you increase the pressure, the molecules have less space in which they can move. That greater concentration of molecules increases the number of collisions. When you decrease the pressure, molecules don't hit each other as often. The lower pressure decreases the rate of reaction.

collision theory rates of reaction

2011-04-02T16:01:00.000+02:00

RATES OF REACTIONS

The rate of a reaction is the speed at which a reaction happens. If a reaction has a low rate, that means the molecules combine at a slower speed than a reaction with a high rate. Some reactions take hundreds, maybe even thousands of years while other can happen in less than one second. The rate of reaction depends on the type of molecules that are combining.

There is another big idea for rates of reaction called collision theory. The collision theory says that the more collisions in a system, the more likely combinations of molecules will happen. If there are a higher number of collisions in a system, more combinations of molecules will occur. The reaction will go faster, and the rate of that reaction will be higher.

Ask About Collision theory

2009-11-17T08:16:00.003+02:00

Here I made a new Section for whome want to ask a FREE Questions about collision theory and any part of my explanation on collision theory ,so feel FREE to ask and I will Answer you ASAP
your friend in success :
Chemist :M.Jonathan

what is the basic collision theory ?

2009-08-29T11:02:00.005+02:00

The basic collision theory aims on some postulates that the any chemical reaction to occurr there is a collision processes or hits between the particles or atoms of the Reactant molecules that will result in breaking existing bond between this molecules and forming new bonds that combine together to form the end products of the Reaction
All the Process is simple as you see but there a lot of concepts you must be aware of for good understood of basic collision theory such as :

The Principles of Quantum Mechanics
Symmetry Operations on the Schrodinger Equation
The Description of Scattering Processes
Formal Scattering Theory
The Two-Body Problem with Central Forces
Scattering by Noncentral Forces
The Lifetime and Decay of Virtual States
Relativistic Description of the Scattering of Spin One-Half Particles by a Force Center
The Scattering and Photoproduction of Pi-Mesons from Nucleons
The Theory of Final State Interactions
Applications of Formal Scattering Theory to Field Theory
Dispersion Theory
Scattering by Systems of Bound Particles

A lot of concepts and theories you should study but also a lot of information about that concepts to help you master the basic collision theory concepts and postulates .

MGoldberger and Kenneth M. Watson arvin L. has wrote resourses Extensively on that theories with a huge index full of the Extensively explaination of basic collision theory and related theories the I mentioned above .
I remember that book was there you can see if they are still showing it

the basic collision theory and related concepts involved by extensively explanation in that book , that amazing Handbook save your time in discovering the whole information ,if you need additional resourses just type it in comments here .

Who invented the collision theory ?

2009-08-27T10:58:00.003+02:00

Max Trautz known as the founder of collision theory and the British scientist William Lewis Who invented the collision theory

but Trautz published his work on collsion theory invention in 1916 and Lewis published his invent on collision theory in 1918

The Collision theory postulate that the chemical Reaction producing the final products after some selective collisions between the Particles of reacting materials ,

collision theory invented by Max Trautz and William Lewis in 1916 and 1918, but due to World War at that time they stay unaware of each other's work

What is the meaning of collision theory chemistry ?

2009-08-27T10:42:00.003+02:00

the meaning of collision theory chemistry is concluded :
that the fact of The reaction will occur when reactant particles collide and from the total collisions only a certain fraction have the energy to connect effectively ; hens will lead to the transformation of reactants into products according to statement of collision theory chemistry .

from this meaning of collision theory we can see that other molecules does not success to connect and collide ,the process lead to production of reactant materials .

And that is why ? as collision theory chemistry states and due to only a portion of the molecules have the enough energy and the right angle of orientation at the moment of impact to break any existing bonds and form new ones.

chemistry related Images for 3D Tubes

2009-07-22T17:27:00.013+03:00

I have collected a dozens of Images of chemistry science
and now Number one collection , about tubes of chemical laboratory and especially in analytical chemistry lab:

Pictures album for Chemistry Items that most frequently used in Chemistry Labs

Chemical Beakers , chemical testing tubes , chemical ignition tubes ,chemical measuring flask ,volumetric glassware Buret ,Buret Titration Equipment,Chemistry Glassware: Flasks, Cylinders, Burets, Funnels;

Factors of Collision Theory Rates of Reaction

2009-07-11T16:07:00.008+03:00

Factors of collision theory influence the rate of a chemical reaction :

collision theory temperature

collision theory concentration of reactants
collision theory catalysts
collision theory surface area of a solid reactant

Pressure of gaseous reactants or products

We will study the effects of temperature or the effects of the concentration of reagents, because they allow you to select a range of values for the control or independent variable. The dependent variable is the rate of reaction. Keep all other variables fixed.

Now shall we discussing each Factors of Collision Theory that effecting on Rates of Reaction individually :
1-How collision theory temperature affects the rate of a chemical reaction?

Two molecules react if they have enough energy. By heating the mixture, you can increase the energy levels of molecules involved in the reaction. The increase in temperature the molecules move faster. This is the kinetic theory. If your reaction is rather between atoms in molecules that you replace the word "atom" for "molecule" in your explanation.

2-How collision theory catalysts influence the rate of catalytic reaction?

Catalysts accelerate chemical reactions. Only trace amounts of catalyst to produce a change in the rate of reaction. It's really because the reaction goes through a different path when the catalyst is present. The addition of further catalyst will be absolutely no difference.

3-what effect of collision theory concentration has on collision theory ?

Increasing the concentration of reactants will increase the frequency of collisions between the two reagents. Thus, the collision theory again. You also need to discuss the kinetic theory in an experiment where you vary the concentration. While you keep the temperature constant, the kinetic theory is relevant. This is because the molecules in the reaction mixture have a range of energy levels. When collisions occur, they are not always result in a reaction. If the two molecules are colliding enough energy, they will react.

4-How does surface area affect a chemical reaction?

Smaller particles have greater surface area than larger particles of the same mass of solid. There is a simple way to visualize this. Take a piece of bread and cut into slices. Each time you cut a slice, you get a surface on which you can spread butter and jam. The thinner you cut the slices, you get more and more slices of butter and jam you can put on them. It is "Bread and Butter Theory". You have found the idea in your biology lessons. By chewing your food will increase the surface so that digestion can go faster.

5-What affect does pressure have on the reaction between two gasses?

In a diesel engine, the compression of the gaseous mixture of air and diesel fuel also increases the temperature sufficient to produce combustion. Increased pressure also results in an increase in temperature. It is not enough in a gasoline engine to burn, for petrol engines need a spark plug. When the air fuel mixture has been compressed, the spark plug ignites the mixture. In both cases, the reaction (combustion) is very fast. The reason is that, once the reaction has started, heat is produced and this will make it go even faster.

Abstract :
The Rates of Reaction affected by Factors of Collision Theory which supposed :

Reaction rates of Collision Theory will increase as this factors increased :

temperature of collision theory increase speed of reaction - concentration of collision theory of reactants increase rate of potential collisions - catalysts of collision theory make the Reaction rapid - surface area of collision theory of a solid reactant maximizing the area of where the reaction occur - Pressure of gaseous reactants or products increase the temperature hens increase the Energy of collision

when the collision theory concentration doesn't affect the rate of the reaction ?

2009-06-30T19:14:00.005+03:00

Cases where Where changes in the collision theory concentration do not effecting on the rate of the reaction.
How the rate of the Reaction could not affected by collision theory concentration
lets see :
When the catalyst is already working as fast as it can

Suppose you use a small quantity of a solid catalyst for the reaction, and a high enough concentration of reagent in the solution so that the catalyst surface is completely crowded to react with the particles.

Increasing the concentration of the solution may not even have any effect because the catalyst is already at its maximum capacity.

collision theory concentration in multi step reactions :
In some multi-step reactions

It is the most important effect of an A 'level point of view. Suppose you have a reaction that occurs in a series of small steps. These measures are likely to have very different rates - the quick and slow.
Example explaining the truth about the collision theory concentration has no effect on Rate of the Reaction :
Suppose two reagents A and B react to these two steps:

The overall rate of reaction will be governed by the speed of A divides X and Y. This technique is described as the rate determining step of the reaction.

If you increase the concentration of A, you will increase the chances of this happening for reasons discussed above.

If you increase the concentration of B, which will no doubt accelerate the second stage, but made little difference to the overall rate. You can image the second stage occurs so quickly that now, when all the X is formed, it is immediately pounced B. This second reaction is already "waiting" for the first to arrive.

The best examples of such reactions comes from the organic chemistry. This is the reaction between an education halogenoalkane (alkyl halide) and a number of substances - including hydroxide ions. These are examples of nucleophilic substitution using a mechanism known as SN1.

Note: The overall rate of reaction is not completely independent of the concentration of B. If you lowered enough concentration, you'll reduce the rate of the second reaction, to the point where it is similar to the rate of the first. The two concentrations of matter if the concentration of B is quite low.

However, for concentrations, we can say that (for a good approximation), the overall rate of reaction is not affected by the concentration of B.

Summary of cases that the collision theory concentration will not affecting the overall Rate of the Reaction :

1-The collision theory concentration has no effect on the reaction rate when catalyst at Max. capacity .
2-If the reaction occurred in multi-steps the collision theory concentration has no effect on the reaction rate .

collision theory concentration affects the rate of the reaction

2009-06-30T19:07:00.009+03:00

collision theory concentration affects the rate of the reaction
Cases where the change in concentration affects the rate of reaction

It is the common case, and this is easily explained.

Collisions involving two particles

The same argument applies whether the response to the collision between two particles or two of the same particle.

high collision theory concentration increase potential collisions
For any reaction to occur, must first particles collide. This is true if the two particles are in solution, or whether one is in the solution and the other solid. If the concentration is higher, the chances of collision are greater.

Reactions involving a single particle

If not a reaction involves a single particle splitting in a way, the number of collisions is irrelevant. What matters now is how many particles have enough energy to react at any time.

collision theory concentration affected by rate changes, do u think this is true ?
Suppose that, at any time in a 1 million particles have enough energy to equal or exceed the activation energy. If you had 100 million particles, 100 of them to respond. If you had 200 million particles in the same volume, 200 of them would now react. The reaction rate was doubled by doubling the concentration.

Now it has been explained that collision theory concentration affects the rate of the reaction by positively speed
i.e ,
High concentration = high reaction rate = completely conversion of Reactants
Low concentration = low reaction rate =partially conversion of Reactants

please comment if you have an explanation ...

collision theory concentration examples

2009-06-30T19:02:00.005+03:00

Zinc and hydrochloric acid
In the laboratory, the granules of zinc reacts slowly with dilute hydrochloric acid, but much faster if the acid is concentrated.

The catalytic decomposition of hydrogen peroxide
Solid manganese (IV) oxide is often used as a catalyst in this reaction. Oxygen is delivered much faster if the hydrogen peroxide is concentrated if it is diluted.

The reaction between sodium thiosulphate solution and hydrochloric acid
It is a reaction that is often used to study the relationship between concentration and reaction rate in introductory courses (eg GCSE). When a dilute acid is added to the solution of sodium thiosulfate, a pale yellow precipitate of sulfur is formed.

As the sodium thiosulphate solution is diluted more and more, the precipitate a longer and longer to form.

collision theory concentration explaination

2009-06-30T18:40:00.004+03:00

what effect concentration has on collision theory ? and collision theory concentration increase cases ;this what we will discuss in a few little assays , but let us first define the concentration :
What is the Concentration ?
Concentration In chemistry is the measure of the quantity of a substance, it is mixed with another substance. This can apply to any kind of chemical mixture, but more often the concept is limited to homogeneous solutions, where he refers to the amount of solute in solvent.

To make concentrated solution, must add more solute, or reduce the amount of solvent and to dilute a solution, we must add more solvent, or reduce the amount of solute.

Unless the two substances are completely miscible, there is a concentration at which no further solute is dissolved in a solution. At this point, the solution is supposed to be saturated. If other fluid is added to a saturated solution, it will not dissolve . However, phase separation occurs, leading to two coexisting phases or a suspension.

and explain in terms of collision theory why increasing temperature and concentration increase reaction ?
The saturation point depends on many variables such as ambient temperature and the precise chemical nature of the solvent and solute.
Analytical concentration includes all forms of this substance in the solution.

CONCENTRATION in Collision theory chemistry :
EFFECT OF CONCENTRATION ON REACTION RATES
collision theory concentration roles : or
how does concentration and the collision theory affect rate of reaction ?
We will describe and explain the way that the evolution of the concentration of the solution affects the rate of a reaction

What happens?
In fact :
For many reactions involving liquids or gases, increasing the concentration of reactants increases the reaction rate. In some cases, increasing the concentration of the reagents in May had little effect in the rate. These cases are discussed and explained later topics .

Double the concentration of the reagents that will not allow you to double the rate of reaction. May it happen like that, but the relationship May be more complicated.

The mathematical relationship between concentration and reaction rate is discussed on the page on the orders of the reaction. If you are interested, you can use this link or read about it later, through the reaction menu .

The examples on this relations all involve solutions . and note that Changing the concentration of a gas is achieved by changing its pressure.
collision theory concentration experiment , to be continue..

Derivation of Collision Theory-Based Kinetics Semiempirical Equations

2009-06-27T15:27:00.003+03:00

A Collision Theory-Based Derivation of Semiempirical Equations for Modeling Dispersive Kinetics and Their Application to a Mixed-Phase Crystal Decomposition

Abstract

In recent works, the author has shown the utility of new, semiempirical kinetic model equations for treating dispersive chemical processes ranging from slow (minute/hour time scale) solid-state phase transformations to ultrafast (femtosecond) reactions in the gas phase. These two fundamental models (one for homogeneous/deceleratory sigmoidal conversion kinetics and the other for heterogeneous/acceleratory sigmoidal kinetics; isothermal conditions), based on the assumption of a “Maxwell−Boltzmann-like” distribution of molecular activation energies, provide a novel, quantum-based interpretation of the kinetics. As an extension to previous work, it is shown here that the derivation of these dispersive kinetic equations is supported by classical collision theory (i.e., for gas-phase applications). Furthermore, the successful application of the approach to the kinetic modeling of the solid-state decomposition of a binary system, CO₂·C₂H₂, is demonstrated. Finally, the models derived appear to explain some of the (solid-state) kinetic data collected using isoconversional techniques such as those often reported in the thermal analysis literature

Peter J. Skrdla

J. Phys. Chem. A, 2006, 110 (40), pp 11494–11500
Copyright © 2006 American Chemical Society

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2009-06-24T19:30:00.006+03:00

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Equations of collision theory chemistry

2009-06-24T19:28:00.017+03:00

Equation of collision theory chemistry derived by Rate constants calculations of the reaction
In Quantum mechanics the collision theory chemistry may defined as :
1. collision theory chemistry is :
a Theory to describe collisions of simple or complex particles, the derivation of collision cross sections from postulated interactions
2. collision theory chemistry is :
the study of properties of collision amplitudes which follow from invariance principles such as conservation of probability and time-reversal invariance .

* Rate constant in state of collision theory chemistry
The rate constant for a bi molecular gas phase reaction as predicted by collision theory, is:

Where:
Z is the collision frequency.
p is a steric factor .(that corrects for low-energy-level collisions.)
Ea is the activation energy of the reaction.
T is the temperature.
R is gas constant.
And the collision frequency is:

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

So that :

the physical chemistry describing the collision theory chemistry as:
A Theory of chemical reaction proposing that the rate of product formation is equal to the number of reactant-molecule collisions multiplied by a factor that corrects for low-energy-level collisions.

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chemistry collision theory applcations (part 1 )

2009-06-24T19:28:00.015+03:00

Collision theory chemistry model :
The collision theory chemistry model of the theory of chemical reactions can be used to explain the observed rates for the two laws in one stage and multi-step reactions. Collision theory chemistry model assumes that the rate of any stage of a reaction depends on the frequency of collisions between the particles involved in this step.

The figure below provides a basis for understanding the implications of the collision theory chemistry of simple collision model, a stage of reactions, such as the following

ClNO2(g) + NO(g) <----> NO2(g) + ClNO(g)

The kinetic molecular theory assumes (related theory to collision theory chemistry) that the number of collisions per second in a gas depends on the number of particles per liter. The rate of NO₂ and ClNO which are formed in this reaction should be directly proportional to the concentration of NO and two ClNO₂

Rate = k(ClNO₂)(NO)

The collision theory chemistry model suggests that the rate of one stage of reaction is proportional to the concentration of reagents used in this step. The rate of duty for a reaction time must therefore agree with the stoichiometry of the reaction .

Example on collision theory chemistry model :

The following reaction, for example, occurs in a single step.

CH3Br(aq) + OH-(aq) <----> CH3OH(aq) + Br-(aq)

When these molecules collide (as collision theory chemistry stated) in the right direction, a pair of nonbonding electrons on the OH-ion can be donated to the carbon atom at the center of the CH3Br molecule, as shown below

When this occurs, a carbon-oxygen forms together with the carbon-bromine bond is broken. The net result of this reaction is the substitution of an OH-ion for a Br - ion. Because the reaction occurs in one step, dealing with collisions between the two reagents, the rate of this reaction is proportional to the concentration of reagents

and the rate (as posted in collision theory chemistry) :

Rate = k(CH₃Br)(OH^-)

Not all reactions occur in a single step. The following reaction occurs in three steps, as shown in the figure below.

(CH₃)₃CBr(aq) + OH^-(aq) (CH₃)₃COH(aq) + Br^-(aq)

In the first step, the (CH₃)₃CBr molecule dissociates into a pair of ions.

First step

The positively charged (CH₃)₃C⁺ ion then reacts with water in a second step.

Second step

The product of this reaction then loses a proton to either the OH^- ion or water in the final step.

Third step

The second and third steps in this reaction are very much faster than first.

(CH₃)₃CBr (CH₃)₃C⁺ + Br^-		Slow step
(CH₃)₃C⁺ + H₂O (CH₃)₃COH₂⁺		Fast step
(CH₃)₃COH₂⁺ + OH^- (CH₃)₃COH + H₃O		Fast step

The rate of the first step is therefore more or less equal to The overall rate of reaction

The first step is also called rate-limiting step in this reaction . Because only one reagent is involved in the rate-limiting step, the overall rate of reaction is proportional to the concentration of only this reagent ; so the rate-limiting step literally limits the rate at which the products of the reaction can be formed .

the summary for collision theory chemistry rate

Rate = k((CH₃)₃CBr)

The stoichiometry of the reaction predicts different rate law for this reaction . Although the reaction consumes both (CH₃)₃CBr and OH^-, the rate of the reaction is only proportional to the concentration of (CH₃)₃CBr.

The following general rules explains The rate laws for chemical reactions in chemistry collision theory :

At any step in a reaction The rate is directly proportional to the concentrations of the reagents consumed in that step.
The sequence of steps, or the mechanism, by which the reactants are converted into the products of the reaction determining The overall rate law for a reaction .
The rate law for the slowest step in the reaction dominates The overall rate law for a reaction .

Collision theory chemistry

2009-06-24T19:27:00.022+03:00

Collision theory chemistry is related to chemical kinetics science almost .
Collision theory chemistry is stated by Max Trautzand William Lewis in 1916 and 1918 .

collision theory chemistry useful :
In qualitative analysis Collision theory explains :
1-how chemical reactions occur .
2-why reaction rates differ for different reactions.

Mechanism of Collision theory chemistry:
Activation energy is The minimal amount of energy needed for reaction to occur .
activation energy released when Particles from different elements react with each other as they hit each other.

The collision is called successful if the elements react with each other , but if the concentration of at least one of the elements is too low, there will be fewer particles for the other elements to react with and the reaction will happen much more slowly.

Reaction becomes rapid in case of collision theory chemistry when:
1-when temperature increases, the average kinetic energy and speed of the molecules increases and this only increases slightly the number of collisions.
2-The rate of the reaction increases with temperature increase because a higher fraction of the collisions overcome the activation energy.
3-high concentrations .

Summary Collision theory chemistry:
when concentration of reactant is high ;and the temperature needed is high , then reaction speed increased more possible collisions occur between molecules , when the collisions is high and Activation energy increased this lead to transforming reactant molecules to products.

Thus collision theory chemistry is achieved

Illustration of the dependence of molecular collisions frequency with concentration in case of collision theory chemistry

Equations of collision theory chemistry :
ch3Br lewis structure
ch3br(aq) + oh - (aq) → ch3oh (aq) + br (aq)

General Focus on Chemistry Science

2009-06-24T19:21:00.003+03:00

Chemistry

Chemistry is the study of interactions of chemical substances with one another and energy.

Chemistry (from Egyptian kēme (chem), meaning "earth"^[1]) is the science concerned with the composition, structure, and properties of matter, as well as the changes it undergoes during chemical reactions.^[2] It is a physical science for studies of various atoms, molecules, crystals and other aggregates of matter whether in isolation or combination, which incorporates the concepts of energy and entropy in relation to the spontaneity of chemical processes. Modern chemistry evolved out of alchemy following the chemical revolution (1773).

Disciplines within chemistry are traditionally grouped by the type of matter being studied or the kind of study. These include inorganic chemistry, the study of inorganic matter; organic chemistry, the study of organic matter; biochemistry, the study of substances found in biological organisms; physical chemistry, the energy related studies of chemical systems at macro, molecular and submolecular scales; analytical chemistry, the analysis of material samples to gain an understanding of their chemical composition and structure. Many more specialized disciplines have emerged in recent years, e.g. neurochemistry the chemical study of the nervous system (see subdisciplines).

Chemistry is the science concerned with the composition, structure, and properties of matter, as well as the changes it undergoes during chemical reactions.