Determining the identity of an organic unknown Essay Example for Free

Determining the identity of an organic unknown Essay When supplied with a organic unknown there are many ways of determining its identity and it is important to use as much information as can be gained to work out the identity of an unknown as many are very similar in physical properties, chemical properties and/or chemical make up. In this experiment I will be using a flow chart to identify the functional group that the unknowns contain, and once I have suggested this I will then use spectra given to me to determine what the identity of the organic unknown is. I have been told that the organic unknown, will one of the following functional groups: Alcohols Probably the most common of these functional groups is the -OH group, which is known as the hydroxyl group. It is NOT the hydroxide ion, OH1-, as it does not have a charge. The dash in front of the OH stands for a single covalent bond, which is what will be formed between the oxygen and a carbon atom. An aliphatic hydrocarbon that has one hydroxyl group attached to a carbon is called an alcohol. The simplest alcohol is methyl alcohol, or methanol. The molecular formula is usually written as CH3OH, because it gives more of a picture of the actual structure than does CH4O. This way of writing the formula becomes more important as the number of carbons increases. Take the case of ethyl alcohol, or ethanol. The parent compound is ethane, so the formula is C2H6O, but C2H5OH gives specific information that the compound is an alcohol and not any other compound. Phenol Colourless solid, partially miscible in the cold water, soluble in organic solvents. Differ in many ways to aliphatic alcohols. Like alcohols contain -O-H group but also a benzene ring. The difficulty in substituting the -OH group is due to the stabilisation caused by the overlap of the p-orbital of the oxygen atom with the bonding in the ring. The situation is similar to that in chlorobenzene. Phenols have many chemical properties i) Acid-base properties Phenol is a stronger acid than water whereas aliphatic alcohols are weaker. The polarity of the hydroxyl bond facilitates the loss of a proton and the formation of a phenoxide ion and the delocalisation in the phenoxide ion also stabilises it as compared with RO- or OH- ions. If electron-withdrawing groups (-Cl) are substituted into the benzene ring the polarity of the O-H bond is increased still further giving still stronger acids. Aldehydes A new class of substituted hydrocarbons arises when an oxygen atom is double bonded to the carbon at the end of the chain. In this case there are two less hydrogen atoms, so instead of three end hydrogens, there is the C=O and only one hydrogen. The simplest aldehyde is, formaldehyde, CH2O. Its IUPAC name is methanal. It has an -al ending as opposed to the -ol ending that alcohols have. These compounds show the generic formula, H-R=O. Ketones A different class of organic compounds results if the C=O occurs somewhere along the chain other than on the end carbon. The simplest ketone has three carbons. It has the common name acetone, and is in most fingernail polishes and removers. It is sometimes called dimethyl ketone, but is more properly called propanone. Break apart the name to see how the name propanone gives a better picture of the compounds formula than does acetone. Â  First of all, the propan- indicates that the parent hydrocarbon is propane, and thus has three carbons. Second, the ending -one goes along with the ending of the name of the class of compounds to which it belongs, ketones. The generic formula for ketones is R-C=O(-R). Carboxylic acids Carboxylic acids have a more complex functional group, and if you look at it, you can see both the C=O of the aldehyde and the -OH of the alcohol. The organic, or carboxyl group, is -C=O(-OH), often written as COOH, or even CO2H. Organic acids may have more than one carboxyl group. The simplest organic acid is methanoic acid, CHOOH, or formic acid, to use the older name. Ants inject formic acid into their victim whem they bite them. The next in line is, of course, ethanoic acid, CH3COOH. Notice the ending, -oic, to the IUPAC name, and -ic, to the common name. There are some very important organic acids, and one of the most important is ascorbic acid, better known as Vitamin C. The generic formula is R-(COOH)x Why are these compounds acids? Well, they must be able to produce at least one hydrogen ion when they are put into solution, since that is the general definition for an acid. Even though these organic acids may contain quite a few hydrogen atoms in the molecule, only select hydrogens are able to be ionized or turned into hydrogen ions. These select hydrogens are those in the carboxyl group (-COOH) The presence of one or more of these groups, therefore, causes the compound to belong to the organic acids. Ester An ester results when there is an oxygen atom between two carbons in the chain. The simplest is dimethyl ester, which has the same molecular formula as ethanol. The way the formula is written to show the ester, rather than the alcohol, is CH3OCH3. There are two other esters of interest, ethylmethyl ester and diethyl ester. You should be able to write the formulas for each of these. Esters are represented as R-O-R, where R and R can be the same or different hydrocarbon units. Method Apparatus i 10 cm3 measuring cylinder i Teat pipette i Test tubes i Electric hotplate Reagents i Bromine water i 2,4-dinitrophenylhydrazine i Tollens reagent i Aqueous sodium carbonate i Lime water i Acidified potassium dichromate Only small volumes of the unknown compound need to be used in each test as they are in a pure form. Therefore I will only use 3cm3 of each reagent and the unknown compound. Test for presence of alcohol:An oxidation reaction must take place. Mix equal volumes (3cm3) of dilute sulphuric acid and potassium dichromate solution. Then add the same volume of the unknown to it. If the solution turns from orange to green then a primary or secondary alcohol group is present. Test for presence of a carbonyl group: A condensation reaction takes place. 2,4-dinitrophenylhydrazine solution is added to the sample, if the solution turns into an orange precipitate then a carbonyl compound is present. Test to distinguish between a ketone and an aldehyde: An oxidation reaction takes place. Add a small volume of sodium hydroxide solution to 3cm3 of silver nitrate solution until a slight precipitate forms, than add ammonia solution dropwise until the precipitate dissolves. Then add a few drops of the unknown sample and warm in a water bath. If a silver mirror forms, then the compound has an aldehyde functional group. Test for presence of carboxylic acid: An acid / base reaction occurs. Aqueous sodium carbonate solution is added to the sample. If effervescence occurs and the gas evolved is carbon dioxide (test gas by bubbling into lime water) then a carboxylic acid group is present. Test for presence of phenol: A substitution reaction occurs. Bromine water is added to the sample and if a phenol group is present then the bromine water decolourises and a white precipitate is formed. Test for ester group: Esters have a distinct fruity smell. There is no simple test to carry out for identifying an ester, so I will determine the sample is an ester by negative results from the previous tests. Saftey Safety is imperative when carrying out experiments in the lab, this is even more true when the identity of a compound is unknown as it could have any dangerous properties, gloves should be used when handling substances and goggles worn, long hair tied back and cuts covered. Flow chart Results of organic tests All organic tests proved negative, apart from the test for an alderhyde although this test did not produce a silver mirror some dark precipitate was formed indicating the likeliness of the presence of an aldehyde. Analysis of spectropic data Conclusion I conclude that the organic unknown is an aldehyde this is because of the results found from the chemical tests performed , the specific aldehyde I believe the unkown to be is benzaldehyde. This is because not only does its physical properties fit those described in text books it also has the right structural formula to fit with the spectropic data provided. benzaldehyde benzaldehyde or benzenecarbonal , C6H5CHO, colourless liquid aldehyde with a characteristic almond odour. It boils at 180i C, is soluble in ethanol, but is insoluble in water. It is formed by partial oxidation of benzyl alcohol, and on oxidation forms benzoic acid. It is called oil of bitter almond, since it is formed when amygdalin, a glucoside present in the kernels of bitter almonds and in apricot pits, is hydrolysed, e. g. , by crushing the kernels or pits and boiling them in water; glucose and hydrogen cyanide (a poisonous gas) are also formed. It is also prepared by oxidation of toluene or benzyl chloride or by treating benzal chloride with an alkali, e.g. , sodium hydroxide. Benzaldehyde is used in the preparation of certain aniline dyes and of other products, including perfumes and flavourings. Evaluation Overall I feel this experiment went very well as I was able to determine both the functional group present and then with the aid of specropic data the exact compound. I carried out the experiment safely following all guideline set in my method. The only test that could have been performed more accurately was the test for an alderhyde that did not produce a silver mirror.

Gravity-Centrifugal-Power-Motor :: essays research papers

SCM-Variation Gravity-Centrifugal-Power-Motor Objectives At chapter Swing-Circuit-Motor (SCM) above, a design was worked out corresponding to build-up of a loop-swing. There, two axis were demanded (system- and excenter-axis) and two  ´wheels ´ did turn within each other. So this will be a rather difficult technical construction. By this chapter now shall be examined, how effect of building-up mechancal oscillations could be realized easier. So only one axis should be neccessary, nevertheless masses should move like at uneven  ´movement of pendulum ´, above this phase shifting by intermediate storage of forces must be guaranteed. Pendulum with radial suspension At previous chapter Mechanical Oscillating Circuit Harald Chmela did mention example of a pendulum with radially working spring, like schematically shown once more at picture EV SKM 31 upside. Around system axis (SA) a pendulum, here called rotor arm (RT, German Rotortrà ¤ger), can swing. At the rotor arm effective mass (MP) can glide inside and outside. That radial movements are limited resp. controlled by a spring element (FE, German Federelement). Potential energy of level is transformed into kinetic energy at downward-phase, opposite energy of movement is re-transformed into energy of high level at upward-phase. In addition, power is stored into spring intermediately, so some later power is restored into pendulums oscillation. Mass will move at an U-shaped track. Mass will show maximum speed at its lowest point of track (A) and there will press down spring at its maximum. Following relaxation of spring will show analog relations of forces, based at symmetry, so this mechanical oscillation will be stable (no friction assumed). Effect of building-up oscillations can only be achieved, if symmetry is broken. This could be done e.g. as shown at picture EV SKM 31 downside. Asymmetric track Tension of spring downside should have to be stored for a short time, e.g. any mechanicsm could allow relaxation of spring some later (B). Counter stored energy then would exist less forces (resulting force of gravity power and centrifugal power), showing upward more and more. Power of spring afterward could move mass easier and faster towards upward-inside (C). Angles speed thus will be accelerated and mass will be brought to higher level (D) than starting level. This mechanical oscillating circuit thus will be build-up without input of energy from outside. Progressive suspension By this concept an asymmetric track is achieved. However, this pendulum swinging resp. effect of build-up oscillations is technically usable only if a momentum is achieved at a constant turning shaft.

Cell phones aloud in school Essay

Most school administrators regard cell phones use as disruptive and distracting devices in class, as well as a form of cheating during tests; so schools made the policy that prohibit cell phones on school properties. But I believe that there are a few reasons why cell phones should be allowed in schools. Restriction of bringing cell phones to school may be good, but it also causes resentment among parents and officials. In the first place, nowadays increasing numbers of parents are purchasing cell phones for their children. They want them to bring along their cell phones at any time, in order to know their whereabouts and enable their children to make contact with them in case of emergencies. Of equal importance, students occasionally must inform their parents or drivers if they have last minute school schedule changes or something has to be done after school hours. Furthermore, there’re only disadvantages to go against parents, and prohibiting cell phones can also lead to inconvenience for students. Most schools only take in the negative effects of allowing cell phones into consideration but never think of the problems it may cause if cell phones are prohibited in school. Likewise the numbers of students that use cell phones to cheat on tests; distract and escape classes are just a few. Therefore there’s no reason for others to pay the price for those who make the mistakes. The teacher shall confiscate one’s cell phone if he or she has done the following things. This will then make the students feel that they’ve received fair treatment. Another reason cell phones should be allowed in school is because students are old enough to know what can be done and what cannot be done. In support of this, students aren’t happy about the fact that only teachers have the privilege of bringing cell phones to school. They feel that they are not being trusted and treated equally by the adults. Subsequently, more of them begin to violate school rule by bringing in cell phones illegally. I often heard them discussing about finding a perfect location to hide their cell phones when they overheard the principal is coming for checking up. Also students should be able to take responsibilities for their own things and actions; so allowing cell phones in school will be a good example. Now that we have discussed the problems of prohibiting cell phones in school, setting general guidelines will be the solution to these problems, using cell phones on appropriate time and location while allowing students to have the freedom to make calls. It does not only eliminate resentment; thus it’s a way to prove that whether students can be trusted or not. Should cell phones be allowed in school?

My Favorite Movie: Avatar Essay

Avatar, the epic movie by James Cameron, the director behind Titanic, is a project that has caused pop-culture ripples. James Cameron conceived the idea of Avatar back when he was working on Titanic. But the technology was not available then to bring his vision to life in the big screen. So instead of making the movie with sub-quality effects, he basically threw it in the drawer and it was not until 2005 that he decided to bring his masterpiece to life. In 2005, Cameron, along with Vince Pace, invented new ways of capturing the performances of the actors. Their team developed a brand-new image-based facial performance capture system which utilizes a head-rig camera and is able to record even the tiniest of facial movements. Avatar was filmed in stereoscopic 3-D using the brand new Fusion Camera System, which took seven years for Cameron and Pace to create, and is now the most advanced system of its kind. That is the reason why the actions of the natives looked so life-like and realistic, and that is because these parts were played by the actors, and the bodies of the Avatars were built around this motion, making each performance different, and making the Avatars more like the actor than any animated character would be. see more:my favourite movie essay Hence, Avatar was very much a live action film, not an animated film. The story took place on the planet Pandora, which, according to 20th Century Fox’s production notes, is â€Å"a moon with an Earth-like environment that orbits a gas-giant planet called Polyphemus in the Alpha Centauri. At 4.5 light years away, Alpha Centauri is our nearest stellar neighbor. And when it is discovered that Pandora is rich in a rare-earth mineral called Unobtainium, the race is on to mine the new world’s resources.† In the movie, Sam Worthington who starred as the film’s hero, Jake Sully, a disabled ex-marine, was called to help the humans convince the Na’vis give up their home tree. But as Jake Sully lived the life of Na’vis through his Avatar, he has learned to love the ways of life and beliefs of of the Na’vis. Sully, having realized what his fellow humans would cause to Pandora and the lives of the natives, eventually turned his back from the orders given to him, and helped the natives fight for their home. The film became a huge hit. It has reached the Five Hundred Million US Dollar mark in 32 days and became the highest-grossing film on January 26th,  2010, with a final worldwide gross of Two point Eight Billion US Dollars, beating Titanic, the previous record-holder and was also written and directed by Cameron, with a worldwide gross of One point Nine Billion Dollars. Sources: Avatar Production and Facts Wikia.com Imdb.com

Free Essays on Black History

by historian Benjamin Quarles best describe what the American Revolution meant for African Americans and their fight for freedom. When a portion of white Americans demanded freedom from Britain, because it was their human right, it led to enslaved African Americans also asking for their freedom from slavery. After the Seven Years War had ended and eliminated French and Spanish threats to American colonies, it weakened the relationship between Britain and the colonies. Since Britain had helped America get rid of these threats, Britain felt that America should be taxed in order to pay for the war. The colonies during this time were used to governing themselves and therefore believed that paying Britain was out of the question. This led to a number of taxes by the British on the colonies and Americans against British products. These events eventually led to the Declaration of Independence and the Revolutionary War. The Declaration of Independence, which was written and adopted by Congress on July 4th, 1776, was written by a slaveholder. In it Thomas Jefferson wrote, â€Å"all men are created equal; that they are endowed by their Creator with certain unalienable rights†¦Ã¢â‚¬ (Hine and Harrold pg. 75). These rights that Jefferson wrote about did not apply to blacks. When blacks read this they believed that these rights belonged to them as well as whites and began to voice their opinions. African Americans then challenged whites to look at what had been written, and forced them change the way they thought about black freedom. When the War for Independence finally began, blacks joined the side of either Patriots or Loyalists. African Americans in the north were eager to join the side of the Patriots becaus... Free Essays on Black History Free Essays on Black History American Revolution â€Å"The Negro’s role in the Revolution can best be understood by realizing that his major loyalty was not to a place nor to a people, but to a principle.†(Hine and Harrold pg.80) These words by historian Benjamin Quarles best describe what the American Revolution meant for African Americans and their fight for freedom. When a portion of white Americans demanded freedom from Britain, because it was their human right, it led to enslaved African Americans also asking for their freedom from slavery. After the Seven Years War had ended and eliminated French and Spanish threats to American colonies, it weakened the relationship between Britain and the colonies. Since Britain had helped America get rid of these threats, Britain felt that America should be taxed in order to pay for the war. The colonies during this time were used to governing themselves and therefore believed that paying Britain was out of the question. This led to a number of taxes by the British on the colonies and Americans against British products. These events eventually led to the Declaration of Independence and the Revolutionary War. The Declaration of Independence, which was written and adopted by Congress on July 4th, 1776, was written by a slaveholder. In it Thomas Jefferson wrote, â€Å"all men are created equal; that they are endowed by their Creator with certain unalienable rights†¦Ã¢â‚¬ (Hine and Harrold pg. 75). These rights that Jefferson wrote about did not apply to blacks. When blacks read this they believed that these rights belonged to them as well as whites and began to voice their opinions. African Americans then challenged whites to look at what had been written, and forced them change the way they thought about black freedom. When the War for Independence finally began, blacks joined the side of either Patriots or Loyalists. African Americans in the north were eager to join the side of the Patriots becaus...

Best Quotes for Toasting Your Wedding Anniversary

Best Quotes for Toasting Your Wedding Anniversary Wedding anniversaries can be almost as important as weddings, particularly when the anniversary is a big one (10th, 20th, 25th, and so forth). Some anniversaries are celebrated with big parties, while others are small, private events. If youre half of a happy couple celebrating their anniversary or have been invited to give a  wedding anniversary toast to the wonderful companionship and undying love that a special couple shares, you may be stuck looking for the right words. Here are a few quotes that should help you create the perfect wedding anniversary toast that commemorates a perfect love. Quotes for Anniversary Toast Examples What can you say about your husband or wife that truly captures your feelings and their spirit? Luckily, some of the worlds great thinkers and writers have come up with just the right words. Emily Bronte Whatever our souls are made of, his and mine are the same. Mother Teresa I have found the paradox, that if you love until it hurts, there can be no more hurt, only more love. Somerset Maugham We are not the same persons this year as last; nor are those we love. It is a happy chance if we, changing, continue to love a changed person. Elizabeth Barrett Browning You were made perfectly to be loved - and surely I have loved you, in the idea of you, my whole life long. Julia Child The secret of a happy marriage is finding the right person. You know theyre right if you love to be with them all the time. Zane Grey Love grows more tremendously full, swift, poignant, as the years multiply. Quotes for Friends and Relatives Youve been invited to an anniversary event, and you want (or have been invited) to make a toast. Whats the right blend of humor and sincerity to celebrate someone elses love?  Here are ideas that run the gamut from snarky to sincere. Robert A. Heinlein May you live as long as you wish and love as long as you live. ​H. L. Mencken Strike an average between what a woman thinks of her husband a month before she marries him and what she thinks of him a year afterward, and you will have the truth about him. Simone Signoret Chains do not hold a  marriage  together. It  is threads, hundreds of tiny threads which sew people together through the years. Doug Larson More marriages might survive if the partners realized that sometimes the better comes after the worse. Rebecca Tilly The middle years of marriage are the most crucial. In the early years, spouses want each other and in late years, they need each other. R. H. Delaney Love builds bridges where there are none. Elben Bano Love that is true never grows old. Khalil Gibran It is wrong to think that love comes from long companionship and persevering courtship. Love is the offspring of spiritual affinity and unless that affinity is created in a moment, it will not be created for years or even generations.

Assignment 1 Essay Example | Topics and Well Written Essays - 1250 words - 1

Assignment 1 - Essay Example One of the key individual who has highlighted the importance of capitalism in his research is Adam Smith who proposed the theory of the invisible hand (Wilber 1998, 7). According to his theory there is a hand that cannot be seen but is guiding a particular economy to achieve the purpose of common good. According to his concept, the government does not have to intervene in the market and the market is regulated itself and this concept is similar to the concept of laissez faire. Strengths Those economists who are considered as liberalist and capitalist in nature are of the idea that the economy under liberalism is ruled by eight basic tenants (Davis 2008, 5). The initial tenant of liberalism and capitalism is that people operate to safeguard their own interest and to achieve their own aims and objectives before considering the interest of others. The second element of liberalism is that market is place where buyers and sellers meet each other in order to exchange goods and services. Th e third element of liberalism is that everyone has a free will to own property and assets should be privatized and not controlled by the government. The fifth element of this kind of economy is that market is governed and guided by the forces of competition. In order to achieve this element of liberalism, the sellers in the market have to operate in such a way that they compete with each other to attract more and more consumers and in order to attract more consumers they compete through the tools of pricing and they try to utilize their resources in the most efficient manner. The sixth basic element of liberalism is that all individuals are free to choose for whom they are going to work and they can even choose the markets they are willing to serve. The seventh element of liberalism is that consumers are the most important part of the market. This principle is in line with Adam Smith’s idea of consumer sovereignty and the consumer is the decider of the number and kind of reso urces that will be used to produce a product and when this production will occur and for whom the production will be conducted. The last element of this form of economy is that government should not intervene in market operations and let the forces of demand and supply dictates the operations of the market. Another major figure who promoted the idea of liberalism and who himself was a believer of liberalism was John Maynard Keynes of the 20th century (Heinberg 2011, 38). According to his believes, the government should not intervene in a particular economy and they have minimum amount of role to play in the market that are created in foreign and local regions. This concept can clearly be witnessed in the BWS (Bretton Woods System) that was witnessed after the era of WWII. A major part of the BWS was the Keynesian Compromise according to which involvement of the state is limited to the operations of their local markets and their involvement is unnecessary in international market oper ations (Bordo 1993, 158). Those economists who are considered as liberals even support the hegemonic stability theory and they assert that market operations that are international in nature are more stabilized if there is presence of hegemon. Hegemon is a term used to refer to the elite or the dominant one who has the power to make