Determine Concentration and Molarity

Determine Concentration and Molarity Molarity is one of the most common and important units of concentration used in chemistry. This concentration problem illustrates how to find the molarity of a solution if you know how much solute and solvent are present. Concentration and Molarity Example Problem Determine the molarity of a solution made by dissolving 20.0 g of NaOH in sufficient water to yield a 482 cm3 solution. How to Solve the Problem Molarity is an expression of the moles of solute (NaOH) per liter of solution (water). To work this problem, you need to be able to calculate the number of moles of sodium hydroxide (NaOH) and be able to convert cubic centimeters of a solution into liters. You can refer to the Worked Unit Conversions if you need more help. Step 1 Calculate the number of moles of NaOH that are in 20.0 grams. Look up the atomic masses for the elements in NaOH from the Periodic Table. The atomic masses are found to be: Na is 23.0H is 1.0O is 16.0 Plugging these values: 1 mol NaOH weighs 23.0 g 16.0 g 1.0 g 40.0 g So the number of moles in 20.0 g is: moles NaOH 20.0 g Ãâ€" 1 mol/40.0 g 0.500 mol Step 2 Determine the volume of solution in liters. 1 liter is 1000 cm3, so the volume of solution is: liters solution 482 cm3 Ãâ€" 1 liter/1000 cm3 0.482 liter Step 3 Determine the molarity of the solution. Simply divide the number of moles by the volume of solution to get the molarity: molarity 0.500 mol / 0.482 litermolarity 1.04 mol/liter 1.04 M Answer The molarity of a solution made by dissolving 20.0 g of NaOH to make a 482 cm3 solution is 1.04 M Tips for Solving Concentration Problems In this example, the solute (sodium hydroxide) and solvent (water) were identified. You may not always be told which chemical is the solute and which is the solvent. Often the solute is a solid, while the solvent is a liquid. Its also possible to make up solutions of gases and solids or of liquid solutes in liquid solvents.  In general, the solute is the chemical (or chemicals) present in smaller amounts. The solvent makes up most of the solution.  Molarity is concerned with the total volume of the solution, not the volume of the solvent. You can approximate molarity by dividing moles of solute by volume of solvent that is added, but this isnt correct and can lead to significant error when a large amount of solute is present.Significant figures can also come into play when reporting concentration in molarity. There will be a degree of uncertainty in the mass measurement of the solute. An analytical balance will yield a more precise measurement than weighing on a kitchen scale, fo r example. The glassware used to measure the volume of solvent also matters. A volumetric flask or graduated cylinder will yield a more precise value than a beaker, for example. Theres also an error in reading the volume, relating to the meniscus of the liquid. The number of significant digits in your molarity is only as many as that in your least precise measurement.

Pegomastax - Facts and Figures

Pegomastax - Facts and Figures Name: Pegomastax (Greek for thick jaw); pronounced PEG-oh-MAST-ax Habitat: Woodlands of southern Africa Historical Period: Early Jurassic (200 million years ago) Size and Weight: About two feet long and five pounds Diet: Plants Distinguishing Characteristics: Prominent fangs; short bristles on body About Pegomastax Some of the most notable dinosaur discoveries dont involve going out into the field with a shovel and pickax, but examining long-forgotten fossil specimens that have been filed away in dank museum basements. Thats the case with Pegomastax, which was recently named by Paul Sereno after he examined a neglected collection of fossils from southern Africa, which had been discovered in the early 1960s and stashed in Harvard Universitys extensive archives. Pegomastax was certainly an odd-looking dinosaur, at least by the standards of the early Mesozoic Era. About two feet long from head to tail, this close relative of Heterodontosaurus was equipped with a parrot-like beak studded by two prominent canines. The porcupine-like bristles that covered its body are reminiscent of the short, stiff, feathery protrusions of another herbivorous dinosaur, the late Jurassic Tianyulong, which was also an early ornithopod of the heterodontosaur family. Given its presumed plant-eating diet, why did Pegomastax have such sizable canines? Sereno speculates that this feature evolved not because Pegoamastax snacked occasionally on insects or rotting carcasses, but because it needed to a) defend itself against larger theropod dinosaurs and b) compete for the right to mate. If longer-toothed males were more likely to survive predation, and also more likely to attract females, you can see why natural selection would have favored Pegomastaxs fangs.

Explaining a recent innovation in your area of interest or expertise Research Paper

Explaining a recent innovation in your area of interest or expertise - Research Paper Example This is a process that has taken to task doctors and scientists worldwide. One of the major setbacks to this work was inadequate finances. Though this is and has been a global problem, states were not able to come together to pool resources so as to support the noble work that the scientists set out to do. It turned out that only few countries provided the financial support to this project, while others showed no interests in the on-going work, yet they too are affected by the virus. The accomplishment was nonetheless realized thanks to the support of the non-governmental organizations and other well-wishers (Grady, 1995). Another great challenge is the fact that the HIV virus replicates very fast, and once it attacks a CD4+ T cell, it quickly makes very many copies of itself. These copies infect other immune cells. Since it makes many copies of itself, it overwhelms the body’s immunity hence weakening the body. This is worsened by the fact that as the replication takes place, there is DNA sequence change that results into different strands of the virus. The vaccine developed should be able to help prevent all these strands. Unlike many other viruses that attack the human body, the primary target of the HIV virus is the immune system, particularly the CD4+ cells. The virus destroys these cells hence making it difficult for the body to protect itself from other infections, even subsequent HIV infections. The vaccine developed therefore has to work to strengthen the system so that the invading virus does not weaken the body, but is able to prepare it to fight off the virus, at the same time leaving the body strong. There are already in existence big companies that manufacture anti-retroviral drugs (ARVs), the drugs currently used to contain the deadly virus. These companies are already making billions in this business and would therefore want to keep making money. An attempt to come up with vaccines is a threat to their business

12 YEARS A SLAVE Essay Example | Topics and Well Written Essays - 500 words

12 YEARS A SLAVE - Essay Example Additionally, the movie talks about the life of an enslaved educated Black man called Northup who later in life turned to abolish slavery in Louisiana. It is a fact that, many Black people have been killed and many have fought back against discrimination and sexual exploitation and these were the martyr’s who should be remembered according to Copleand. In the author’s eye, solidarity and unity is still a big issue for black people as they are mostly struggling to gain respect and acceptance within the white community. The book and film both tells us that, if one looks at history, many black people had taken the courage to fight for their rights and their effort should be taken as guidance by our community. In fact, black people are as valuable as white person from a religious perspective. In her book (Copeland,2010,pg.113) â€Å"Copeland’s theological anthropology assiduously reveals a carefully developed understanding of historic black bodies in relation to the body of Christ† The author in her book recommends that the history of martyr’s should lead the people to fight for solidarity and peace among each other. In the same way, the movie â€Å"Twelve Years of Slave† is a powerful one which communicates to the audience the life of a black slave. The movie is based on the book written by Solomon Northup where the experience of him as a slave is recounted. He was an educated man and stood firm against racial bias of white men in those times. This man can be taken as a role model as he was an educated and free man till his adult times but later turned in to freedom fighter for the slave community in Louisiana. His life was unusual as he was black person who got kidnapped and sold into slavery where he spent twelve long years in pain. Northup can be seen as a martyr as explained by Copeland and should be followed by new generation to find peace and solidarity in their

The Marketing Environment Essay Example for Free

The Marketing Environment Essay The marketing environment surrounds and impacts upon the organization. There are three key elements to the marketing environment which are the internal environment, the microenvironment and the macroenvironment. Why are they important? Well marketers build both internal and external relationships. Marketers aim to deliver value to satisfied customers, so we need to assess and evaluate our internal business/corporate environment and our external environment which is subdivided into micro and macro. Internal Environment The internal environment has already been touched upon by other lessons on marketing teacher. For example, the lessons on internal marketing and also on the functions within an organization give a good starting point to look at our internal environment. A useful tool for quickly auditing your internal environment is known as the Five Ms which are Men, Money, Machinery, Materials and Markets. Here is a really quick example using British Airways. Looking internally at men, British Airways employees pilots, engineers, cabin crew, marketing managers, etc. Money is invested in the business by shareholders and banks for example. Machinery would include its aircraft but also access to air bridges and buses to ferry passengers from the terminal to the aircraft. Materials for a service business like British Airways would be aircraft fuel called kerosene (although if we were making aircraft materials would include aluminium, wiring, glass, fabric, and so on). Finally markets which we know can be both internal and external. Some might include a sixth M, which is minutes, since time is a valuable internal resource.

Analysis of Dickinson’s Pain has an Element of Blank :: Element Blank

Analysis of Dickinson’s Pain has an Element of Blank      Although cryptic in language and structure, Dickinson gives her work an instinctually vivid sense of emotion.   Her examination of the feeling of pain focuses in on only a few of the subtler nuances of pain that are integral parts of the experience.   She draws in on an "Element of Blank" that she introduces in her opening line.   In exploring pain, she proposes that this "blankness" is a self-propagating force that is subject to the dynamic forces of time, history and perception, but only to an extent. Her first mention of "Pain" in the first line does not distinguish this particular emotion as being of a particular brand of pain.   She substitutes no other words for "pain."   By suggesting no other words for "pain," she chooses the most semantically encompassing term for the emotion.   She thus gives her work the responsibility of examining the collective, general breadth of "pain."   Her alternatives offer connotations that color her usage of "Pain": the sense of loss in "grief" and "mourning" or the sense of pity in "anguish" and "suffering."   She chooses the lexical vagueness of "Pain" to embrace all these facets of the emotion.    In introducing the "Element of Blank," it becomes the context that she thus examines pain.   The exact context of "Blank" possesses a vagueness that suggests its own inadequacy of solid definition.   Perhaps this sense of indefinition is the impression that this usage of "Blank" is meant to inspire.   In this context, this "blankness" is suggestive of a quality of empty unknowingness that is supported by the next few lines: "It cannot recollect When it begun."   This inability to remember raises a major problem with respect to the nature of "Pain;" namely whether Dickinson is choosing to personify "Pain" by giving it a human quality like memory, or is in fact negating the humanity of making it unable to remember.   Several lines below, she suggests that "Pain" does in fact possess some sort of limited sentient ability in recognizing "Its Past - enlightened to perceive."   It is very possible that it is the "Pain" that is being enlightened or perceiving. These conscious acts of giving "Pain" some sort of capacity of awareness personify "Pain" to some extent.    In continuation of "Pain's" inability to remember, She proceeds, "It cannot recollect When it begun - or if there were A time when it was not.

“In Praise of Cultural Imperialism” by David Rothkopf Essay

In the article, In Praise of Cultural Imperialism, David Rothkopf illustrates a progressive new world order where information is the new global currency and the United States, â€Å"the indispensable nation,† is the bank. In his article, Rothkopf contrasts the victimizing tendencies of ‘cultural barriers’, which are the unmistakably causing ethnic, religious, ideological, tribal or nationalistic conflicts, to the uniting tendencies of western globalization. Rothkopf predicts the inevitable merging of all the cultures under the common benefits originating from globalization once â€Å"they have realized that to compete in the global marketplace they must conform to the culture of that marketplace† The United States whose policies are evidently â€Å"the best model for the future† will lead this next step in civilization’s evolution, all the while making sure that â€Å"if common values are being developed, they be the values with which Americans are comfortable.† Rothkopf further states that it is in the US’s best interest â€Å"to encourage the development of a world in which the fault lines separating nations are bridged by shared interest† ultimately leading to a more peaceful and tolerant future: â€Å"Globalization is a vital step toward both a more stable world and better lives for the people in it.† Rothkopf, the former Deputy Undersecretary of the Commerce Department under the Clinton Administration and now the president of an international advisory firm, is also an adjunct professor of international and public affairs at Columbia University. Consequently, his views clearly demonstrate a pro-American capitalist’s stance on the issues pertaining to American economics, cultural imperialism and foreign policy. In his article, Rothkopf describes the power of culture and its influence over this new age global environment, with its power to â€Å"bind and to divide in a time when the tensions between integration and separation tug at every issue that is relevant to international relations.† Moreover, he claims that although critics of globalization may condemn the â€Å"homogenizing influences of globalization,† the effects of globalization are more consistently positive than negative. This is because globalization has an integrating dimension to it. Rothkopf believes that the â€Å"United States is in a position not only to lead in the 21st century as the dominant power of the Information Age, but to do so by breaking down the barriers that divide nations–and groups  within nations–and by building ties that create an ever greater reservoir of shared interests among an ever larger community if peoples† This â€Å"removal not only of cultural barriers but of many of the negative dimensions of culture† could only result in stability†¦right? Rothkopf views could be easily dismissed, as an arrogant fantasy-ridden interpretation of the future. However, although many cultures may not see the benefits of melting themselves into an existence that is in every aspect dominated by western values, the influence of American culture on the rest of the world is evident. Whether this influence will or has been completely positive has yet to be proven. Although Rothkopf believes that globalization is the key to a peaceful future whose culturally uniting fundamentals lie with the United States, he underestimates the complex nature of culture and its strength in relation to globalization. Culture is not something that can be simply defined as Webster’s Third New International Dictionary does, nor will it be easily moulded into a tool to be used for the expansion of American interests. Many cultures around the world, such as in the Muslim block, guard their culture and religion with their lives, for culture and religion are one in the same in Islam. As was illustrated on September 11th, many will even sacrifice their lives for causes they perceive threaten the existence of their culture/religion. Another aspect of globalization that Rothkopf does not develop is the apparent social stratification created by globalization. It is arguable that to sustain globalization, cheap labour must readily available. If undeveloped countries become developed and the poor majority become empowered, where will the cheap labour come from? Although Rothkopf may bring attention to the overbearing extension of American cultural values over the globe, he underestimates how the rest of the worlds’ varied and contrasting cultural values will effect the global environment. Consequently, his extremely biased perspectives undermine some of the more valid points of his article.