Silica Gelgertertrsdfgdfhjrhtfr Chemistry Essay

821 words - 4 pages

Silica gel
Silica gel was patented by chemistry professor Walter A. Patrick at Johns Hopkins University, Baltimore, Maryland in 1919. The substance was known to exist as early as the 1640s.
In chemistry, silica gel is used in chromatography as a stationary phase. In column chromatography, the stationary phase is most often composed of silica gel particles of 40-63 micrometres. In this application, due to silica gel's polarity, non-polar components tend to elute before more polar ones, and this process is called normal phase chromatography. However, when hydrophobic groups are attached to the silica gel, then polar components elute first, and the method is referred to as reverse phase chromatography. Silica gel is also applied to aluminium or plastic sheets for thin layer chromatography.
In some cases, chelating groups have been covalently bound to silica gel. These materials have the ability to remove metal ions selectively from aqueous media. Chelating groups can be covalently bound to polyamines, which in turn have been grafted onto a silica gel surface, producing a material of greater mechanical integrity. Silica gel may also be combined with alkali metals to form a reducing agent.
Silica gel is most commonly encountered in everyday life as beads in a small paper packet. In this form, it is used as a desiccant to control local humidity to avoid spoilage or degradation of some goods. Since such packets may resemble sachets of sugar or salt and because silica gel may have added toxic chemical indicators, silica gel packets usually bear warnings for the user not to eat the contents.
Description of the chemical structure of silica and silica gel.
Silica gel is a granular, vitreous, porous form of silicon dioxide made synthetically from sodium silicate. Silica gel contains a nano-porous silica micro-structure, suspended inside a liquid. Most applications of silica gel require it to be dried, in which case it is called silica xerogel. For practical purposes, silica gel is often interchangeable with silica xerogel. Silica xerogel is tough and hard; it is more solid than common household gels like gelatine or agar. It is a naturally occurring mineral that is purified and processed into either granular or beaded form. As a desiccant, it has an average pore size of 2.4 nanometers and has a strong affinity for water molecules.
Silica gel is non-toxic, non-flammable, and non-reactive and stable with ordinary usage. It will react with hydrogen fluoride, fluorine, oxygen difluoride, chlorine trifluoride, strong acids, strong bases, and oxidizers. Silica gel is irritating to the respiratory tract and may cause irritation of the digestive tract, and dust from the beads may cause irritation to the skin and eyes, so precautions should be taken. Crystalline silica dust can cause silicosis, but synthetic amorphous silica gel is indurated, so does not cause silicosis. Additional hazards may occur when doped with a humidity...

Other Essays On Silica Gelgertertrsdfgdfhjrhtfr - Chemistry - Essay

Phineas And Gene A Comparitive Essay

1538 words - 7 pages Phineas and Gene: A Comparative Study Throughout the story, Phineas and Gene, the two main characters, showed a number of contrasting traits. Phineas was a confident, non competitive, naive, irresponsible, and unintelligent person throughout the story, whereas Gene, Phineas' roommate, was insecure, competitive, mature, responsible, and intelligent throughout the story.Phineas had a confident nature in everything he did. As Phineas and Gene first

Mafia Essay

2008 words - 9 pages Mafia. What does this word mean? The actual members of the Mafia aren't even sure where the word first originated or what it really means. One of the theories as to where the word came from is from Sicily, where people would yell " Morte alla Francia, Italia anela!" (Death to France, Italy groans!), therefore forming the acronym MAFIA. Others claim the word derived from the battle cry of rebels who slaughtered thousands of Frenchmen after a

Baseball Strike

1354 words - 6 pages GAME OVER! "I don't like it. People won't be able to come to these games anymore, and I don't like that". A sad nine - year - old fan voices his concerns on the 1994 major League Baseball strike. The '94 baseball season has come to an abrupt end. Players have ceased play because they feel they are being treated unfairly with the owner's plan to impose a salary cap. Owners are finding it difficult to come to terms with their own disagreements

Worst experience

299 words - 2 pages I wanted to lie down and cry. When I got home from the student/teacher/parent conference in fifth grade my mind was in shambles. After I had done everything possible to pass math, my fifth grade teacher was actually telling my Parents about my alleged poor effort. Poor effort? Didn't I do every homework assignment? Didn't I study every night and miss my favorite television show "Full house"? From an early age, I had been taught that grades are

Multinational Companies

2058 words - 9 pages Multinational Companies: Out for Profit Without Regard for Life                  What a company usually wants for its business is for it to be an successful establishment and to make an abundance of profit. Some businesses do not pose any concern on what they have to do to make this profit as long as it done. Multinational companies are firms with their home base in one country and operations in many other nations. (Molyeux, 133

Middle Adulthood 2

675 words - 3 pages The Dictionary of Social Work roughly defines middle adulthood as the period between forty-five and sixty-four years of age. There are four main tasks in this stage. They include meeting intimacy and family needs, satisfying achievement needs, taking care of elderly parents, and coping with end of life issues. Erikson identifies the need for achievement during midlife, which fits into his stage of generativity vs. stagnation. Success in adulthood

Political socialization

461 words - 2 pages Political Socialization There are many ways that our ideas are shaped and influenced as we grow up. This process by which we develop certain ways of thinking is called political socialization. There are three main influences which change and shape us being, the family, the mass media, and formal education.The family definitely has the greatest impact on us as we grow. This is primarily because ever since the beginning of childhood we are exposed

Procrastination and regrets

533 words - 3 pages Procrastination and Regrets It's Thursday afternoon and Jack has nothing to do except his homework. However, Jack doesn't feel like doing his homework, so he thinks to himself "I'll do my homework tomorrow night and go to a house party tonight." Ah yes, like many other young adults, Jack has resorted to procrastination. The procrastination bug, like young adults has also become abundant in parents.One thing that many young adults procrastinate

Frank o haras the day lady die

398 words - 2 pages In his poem, "The Day Lady Died", Frank O'Hara refrains from using all the conventional patterns of elegiac poetry. Instead of the common reflection of grief, utilizing tragic laments and a recount of greatness now gone, O'Hara's seemingly ordinary poem very subtly evokes a sense of loss. At first, O'Hara's poem appears to be the account of a very typical day. His classic "I do this and I do that" style, accompanied by the simplistic description

The best way to make cappuccin

395 words - 2 pages The best way to make cappuccino is to do it yourself. Do not rely on the abilities of a coffee shop or a restaurant chain to create your perfect drink. Shops like Bernie's and the Gourmet Bean will not have the time to make your cappuccino individually because their goal is to stick with one recipe and mass produce it. These chain shops may have a larger variety to offer, but if quality and perfection are what are what you crave, your best bet is

The Use Of The Internet In Mar

1245 words - 5 pages Computing (IT)- essay by matthew foote Will the internet keep the U.K competitive in a world market, in terms of industry? Recently there has been emphasis for electronic business. Judging by IBM's recent advertising campaign you would be forgiven for thinking that launching a company website leads to instant profits. IBM 's portrayal of a grandmother taking her olive oil business from rural Greece into global markets neatly demonstrates the

Similar Papers

Persuasive Essay Gay And Lesbi

623 words - 3 pages Persuasive Essay - Gay and Lesbian Rights "If anyone says, 'I love God,' yet hates his brother, he is a liar. For anyone who does not love his brother, whom he has seen cannot love God, whom he has not seen," John 4:20. So, why do heterosexual people hate homosexuals? They are ordinary people with a different lifestyle who would simply like to be treated with respect. Many organized religions believe that a 'gay' lifestyle is wrong. But, if

Mark Mcgwire Vs Sammy Sosa Essay

1206 words - 5 pages Although a lot of people play baseball two names that come to mind are Mark McGwire and Sammy Sosa. McGwire and Sosa are very good hitters but are also so very different hitters. McGwire and Sosa are very great athletes who share apart of baseball history. McGwire and Sosa are good players but off the field they are very charitable individuals. McGwire and Sosa have many similarities and differences. IT is hard to compare Mark McGwire and

Master And Slave. An Analysis

495 words - 2 pages Each of the characters in The Tempest finds themselves in bondage. However, by the end of the story, the same characters are set free from whatever enslaves them. A few characters one can see enslaved are Prospero, Miranda, Ariel, and Caliban.Prospero is in bondage to his magic. Since his exile by his brother from his dukedom in Milan, he has had but a few books to help pass the twelve long years. During this time, he becomes very proficient in

Methods Of Therapy Essay

2480 words - 10 pages METHODS OF THERAPY Therapy, from a psychologist's viewpoint, has many different meanings. It can be physical or psychological, or even both. In this paper, several different aspects of therapy will be discussed. First the word therapy will be defined more clearly, and then psychotherapy and how it differs from other interactions yet is also similar. Next therapy will be examined from the Psychodynamic, Cognitive and Humanistic-Existential points