Chemistry Chimie كيمياء

Important: If there is problem in download, see Home page - How to download -.
Please report links do not work by writing a comment below or sending a message by Contact page.

هــام: اذا كان هناك مشكل في التحميل، شاهد الصفحة الرئيسية -كيفية التحميل-.
الرجاء الابلاغ عن روابط لا تعمل عن طريق كتابة التعليق أدناه أو إرسال رسالة عن طريق صفحة اتصل بنا.

To download from FilesIn: User IDMAN Please desable It

للتحميل من FilesIn  : مستعملي IDMAN يفضل تعطيله

------------------------------------

1- Softwares

In construction

2- Learning by Simulations

To be continued

5- Overlapping Chromatographic Peaks

In chromatography a common problem is the correct quantification of overlapping peaks. Given that the two peaks are both at the baseline of the chromatogram, the separation of the two peaks (and the subsequent quantification) is performed by selecting the minimum between the two peaks as the separation line. While this approach is quite reliable if the peaks have the same height, it becomes more and more prone to considerable errors if the heights of the two peaks do not match (which is the common case).

This program simulates the quantification error made when dealing with chromatographics peaks of unequal height. The user may experiment with different peak positions, heights and peak widths. 

Download:

English version http://aa.vg/ljtihlkbm4fr [323kB] 

German version http://aa.vg/5h37z1jqo4hr [324 kB] 

4- Sector Field MS

The magnetic sector field is - among other principles such as electric quadrupole fields, or flight time measurements - one of the most often used principles for commerical mass spectrometers. The principle is easy to understand: a beam of accelerated ions is directed into a magnetic field whose orientation is perpenticular to the beam. The magnetic field thus forces the charged particles on different circular trajectories, whose radii depend on the strength of the magnetic field, the accelerating voltage, and on the mass of the particular ion.

Keeping all but the magnetic field constant results in a separation of the ions according to their mass. Since the detector has a narrow entry split, it "sees" only a small fraction of the entire ion beam fan, i.e. those ions which travel along the circular trajectory connecting both the exit slit of the ion source and the entry slit of the detector. All other ions collide with the inner wall of the evacuated separation system (a small rectangular tube of non-magnetic material). 

The program ms_sectorfield simulates the separation of ions of different masses in a magnetic sector field. The user can adjust both the accelerating voltage and the magnetic field strength, and select from a small number of substances, whose mass spectra have been provided by NIST (courtesy S. Stein of NIST). 

Download:

English version http://aa.vg/iz7oj31slij5 [387 kB] 

German version http://aa.vg/uafqqzczjd66 [387 kB] 

3- Atomic Spectra

Atomic spectra may be used to quantitatively determine more than 70 chemical elements. In order to be able to detect the atomic spectrum, the atoms or ions have to be separated from one another, i.e. the atoms have to be in a gaseous state. This can be achieved by massively heating the substances to be determined (typically the temperature is several thousand degrees). When the gas heats up, it emits light of various characteristic wavelengths. For hydrogen the resulting spectrum obeys a very simple relation:

where n_i and n_f are positive non-zero integers with n_i > n_f and R_H is a constant called Rydberg's constant:

R_H = 1.09710⁷ m^-1.

Apart from chemical analysis atomic spectroscopy is of considerable importance for the investigation of stars, looking for elemental compositions which could enable life in some form. The interest in atomic emission and absorption lines can be traced back to the late 18^th and the early 19^th Century when Fraunhofer discovered dark lines in the spectrum of the sun light.

 f you would like to experiment with spectral lines of selected elements, you can use the program AtomSpec which allows the user to select from several chemical elements. The spectrum may be zoomed to view details of the atomic spectral lines.

Download:

English version http://aa.vg/615593albvgh [266 kB] 

German version http://aa.vg/hr3n6bwkylxx [266 kB] 

2- Molecular Formulas

    If we know the molecular weight of a substance we implicitely know the atomic composition of that substance - provided that the molecular weight is known to an accuracy which is sufficient to distinguish between molecules having the same nominal mass.
To explain this, let's have a look at a very simple example: suppose we know that our substance has a molecular weight of 28. A quick calculation (considering only the nominal masses of the most abundant isotopes of carbon, hydrogen, oxygen, and nitrogen - 12, 1, 16, and 14, respectively) shows that there are three substances which all have the same molecular mass of 28: C₂H₄ (ethene), CO (carbon monoxide) and N₂ (nitrogen gas).

Now, the important point is not to forget that the nominal masses are just for convenience. The actual masses of the four elements are:







¹²C = 12.00000
¹H = 1.007825037
¹⁶O = 15.99491464
¹⁴N = 14.003074 From this you can easily calculate that the actual molecular masses of the three substance having a nominal mass of 28 are:

• C₂H₄ = 28.031300148
• N₂ = 28.006148
• CO = 27.99491464

The smallest difference between the three masses is between CO and N₂, showing a diffence of 0.0112 mass units. In other words, if we know the molecular mass to an accuracy of 0.0056 masses (half the minimum difference) we can easily distinguish between the three molecules having a nominal mass of 28.
This simple example shows the principle of finding the atomic composition by means of mass spectrometry. You simply have to determin the mass with an accuracy high enough to reduce the number of possible candidates to a single molecule. Of course, in practice the molecular masses of interest are much higher and the number of possible candidates increases exponentially if we do not take countermeasures, such as a chemical plausibility check. 

The program MolForm allows to calculate all possible molecular formulas of a particular mass. The user may set the molecular mass and its tolerance (accuracy). This example shows the possible formulas for molecules containing C, H, O, N, and Cl atoms.

Download:

English version http://aa.vg/vwod418b55lv  [266 kB] 

German version http://aa.vg/33gbd30pv3jq [266 kB] 

1- Console of a Mass Spectrometer

A mass spectrometer is a device which can perform accurate chemical analysis (both quantitative and qualitative). Although there are several different technical implementations (sector field, quadrupole, time of flight) all of these devices are based on the same idea: the molecules under investigation are first broken up and then the type and the amount of fragments are investigated. The kind of fragments provides information on the chemical structure of the original molecule, the amount of fragmented ions allows to determine the quantities. Regardless of the actual ionisation and separation technique all kinds of mass spectrometers eventually yield a mass spectrum, which is a line spectrum showing the fragment mass on the x-axis and the number of generated ions on the y-axis.

  This program ms_scope simulates the console of a mass spectrometer. The user may experiment with different resolutions and mass ranges. Ambient air, pregnene, 6-methyl-5-nonen-4-one and perfluorokerosene may be put into the simulated mass spectrometer.

Download:

 English version http://aa.vg/onx29mileq95 [263 kB] 

German version http://aa.vg/yjw5v3v5m11h [264 kB] 

3- Books

English

To be continued

___________________________________________________________________________

6- Macrocyclic Chemistry: New Research Developments

 

Daniel W. Fitzpatrick, Henry J. Ulrich, "Macrocyclic Chemistry: New Research Developments"
English | 2010 | ISBN: 1608768961 | 517 pages | PDF | 6,9 MB

A macrocycle is, as defined by IUPAC, 'a cyclic macromolecule or a macromolecular cyclic portion of a molecule'. In the chemical literature, organic chemists may consider any molecule containing a ring of seven or more atoms to be a macrocyle. Co-ordination chemists generally define a macrocycle more narrowly as a cyclic molecule with three or more potential donor atoms that can co-ordinate to a metal centre. This book brings together the latest research results from around the world.

 

 

 http://www.filemsg.com/ajm2252u7g6o

or

http://www.filedwon.com/oudtqp263ulf/1608768961_MacroChem.pdf.html

___________________________________________________________________________

5- Workbook for Organic Chemistry

Jerry Jenkins, "Workbook for Organic Chemistry"
English | 2009 | ISBN: 1429247584 | 512 pages | PDF | 3,9 MB

Jerry Jenkins’ extensive workbook provides approximately 80 problems per topic with full worked out solutions. The perfect aid for students in need of more problem-solving, the Workbook for Organic Chemistry can be paired with any organic chemistry text on the market. For instructors interested in online homework, W.H. Freeman has also placed these problems in WebAssign.

 http://www.filemsg.com/x4e7jfgogem8

or

http://www.filedwon.com/obafmt280m86/1429247584Work..Org._Chem.pdf.html

________________________________________________________________________________

4- Inspection, Prevention, Control, and Repair of Corrosion

Avionics Equipement

Link:   http://www.filesin.com/4023D216773/download.html

________________________________________________________________________________

3- Handbook of chemistry

 Link: http://www.restfile.com/zwjtdss7w9ah/chem-v1.pdf.html

________________________________________________________________________________

2- The Chemistry of Paints and Painting 

    is a free textbook on chemical aspects of painting. This ebook is based on the printed copy of a book written by Sir Arthur H. Church in 1915. approx. 180 pages, 10 figures

 2.2 MB

Link:   http://www.restfile.com/wbrq2fwlwpre/The_Chemistry_of_Paints.zip.html

________________________________________________________________________________

1-  General Chemistry

    is a free textbook on the fundamentals of chemistry This book is currently under construction.

 2.2 MB

Link:    http://www.restfile.com/ip7ypqxddn46/General_Chemistry.zip.html

________________________________________________________________________________

عــربـــــــــــيــة

 يــتــبــع 

________________________________________________________________________________

8- السلامة_في_المختبرات_الكيميائية
http://www.restfile.com/matp7ej6dntc/السلامة_في_المختبرات_الكيميائية.pdf.html

_________________________________________________________________________________

7- أساسيات_الكيمياء_الفيزيائية-عملي

http://www.restfile.com/01bv85tx0mgv/أساسيات_الكيمياء_الفيزيائية-عملي.pdf.html

_________________________________________________________________________________

6- أساسيات_الكيمياء_الفيزيائية-نظري

http://www.restfile.com/zz8afo8wwvhp/أساسيات_الكيمياء_الفيزيائية-نظري.pdf.html

_________________________________________________________________________________

 5- أساسيات_الكيمياء_العضوية-عملي

http://www.restfile.com/fkc4nlw2mhcz/أساسيات_الكيمياء_العضوية-عملي.pdf.html

________________________________________________________________________________

4- أساسيات_الكيمياء_العضوية_-_نظري

http://www.restfile.com/841bk852y6he/أساسيات_الكيمياء_العضوية_-_نظري.pdf.html

________________________________________________________________________________

3- الكيمياء_العامة
http://www.restfile.com/58gk4qlb2zge/الكيمياء_العامة.pdf.html

_________________________________________________________________________________

2- أساسيات الكيمياء التحليلية - عملي.pdf
http://www.restfile.com/2k5evmviluup/Basic_Anal_Chem_Pratique.pdf.html

_________________________________________________________________________________

1- أساسيات الكيمياء التحليلية - نظري.pdf
http://www.restfile.com/jel5sk529lue...Theor.pdf.htm