Molar Mass of a Solid Essay Example for Free

Molar Mass of a Solid Essay Abstract: The purpose of this experiment is to determine the molar mass of an unknown solid. The freezing point of a solvent (Cyclohexane) was determined, and compare to the freezing point of Cyclohexane with the addition of two different concentration of unknown solid. The pure substance of Cyclohexane has defined physical properties. However, when a solute is added these properties are determined by the amount of solute added, also known as colligative properties. The temperature of the freezing point was lowered when the solid was added and it decreased as the concentration of the solid increased. The molality of the solute was determined, which was then used to calculate the molar mass of the solid for both trials. An average of the molar mass of the unknown solid was calculated to be 286.87+1.796g/mol with a %RSD of 0.626%. The purpose of the experiment was to obtain the molar mass of an unknown solid. The molar mass is determined by dissolving the unknown compound into a pure liquid with defined physical properties, in this case Cyclohexane. When dissolving a solute, it forms a homogeneous solution, in which the solvent of the solution physical properties are not longer defined, but depends on the amount of solute added. Whenever a substance is dissolved in a solvent, the vapor pressure decreases. When the vapor pressure decreases, it also lowers the boiling and freezing point of the solvent and increases the osmotic pressure. These four properties are known as the colligative properties, the magnitude of the changes depends on the amount of solute dissolve; the changes are directly proportional to each other. The higher the solute concentration, the higher the changes of vapor pressure, therefore, a lower freezing point. It is hypothesized that the freezing point temperature will decreased, if there is a higher concentration of the solid added to the soution. Vapor pressure is th e  pressure exerted by a vapor when the vapor is in a state of dynamic equilibrium with its liquid. When a nonvolatile solute is dissolves in the solvent, solute molecules occupy a part of the surface area. This allows molecules into the vapor state, lowing the vapor pressure of the solvent. When the vapor pressure lowers, the boiling point elevates, due to the presence of the solute. Solute added to the solvent affects the freezing point, the energy of the solvent lowers to increase the magnitude of the intermolecular forces for the molecules to get together to form a solid. The colligative properties are useful for determining molar masses of unknown nonvolatile solute. At low concentrations of a nonvolatile solute, the freezing–point of depression of a solvent can be determine by Tf = Kf (solvent) -Tf (solution) = Kf m. Changes in freezing point Tf are directly proportional to the molality, m, of the solute in solution (molality, m = mol solute/ kg solvent). The freezing-point constant, Kf for Cyclohexane is 20ËšC †¢ k/mol, which is used to obtain the amount of moles of solute in the solution, which is inversely proportional to the change of freezing point Tf. The molal mass obtained is essential to obtain the molar mass of the unknown solid (solute). The molal mass shows the unknown amount of moles of solute are need it per kilogram of solvent. Acquiring the number of moles of solute and analyzing it with the grams of solute measured in the laboratory obtaining the molar mass of the unknown solute.i The cooling behavior of a solution different from a pure liquid solution when a solute it’s added. Te temperature at which the solution begins to freeze is lower than the pure solvent. The freezing point also lowers when there is a higher concentration of solute added to the solution. The molar mass of unknown solid can be determined by any of the colligative properties, the freezing point is not an exception and by knowing the mass of solute and temperature of the freezing point, the molar mass can be obtained. Discussion: The freezing point depression is a colligative property of solutions, which is based only on the amount of solute added and not the defined chemical and physical properties of the substance. The freezing point of Cyclohexane observed was 4.97ËšC, from the cooling curve (Figure 1). Freezing point values of Trial 1 and Trial 2 were collected, to compared to the freezing point of Cyclohexane and determine he depression of the solute. The unknown solid yielded a freezing depression of 3.64ËšC for trial 1, and 2.84ËšC for trial 2 (Figure 2 3). These values were compared to the original mass of unknown solute added to the Cyclohexane and the approximate molar mass of  the unknown solid. The molar mass that was calculated for trial 1 was 288.14-g/mol, while trial 2 was 285.60-g/mol (Table 3). The average of the molar mass was calculated, and the molar mass of the unknown solid observed was approximately 286.87-g/mol. When calculating the standard deviation was obtain only +1.796g/mol when comparing both trials to the mean. The values are apparently close up together, making them highly precise, however, is unknown if the values are accurate, the unknown solid actual molar mass still unknown. The relative standard deviation percent, obtained was 0.626% (Table 3); this measurement expresses precision of the data, the smaller RSD the greater the precision for the average value of the data. The %RSD, is extremely low, making it the results a tremendously precise data of the mean. However, there was a possible error that could have affected the results. The error occurred during recording the cooling temperature of trial 1, the ice melted and the test tube was removed to add more ice into the beaker. Also, while recording the temperature of the Cyclohexane upon addition of unknown solid, the sample was not stir and therefore the value could have probably been invalid. Constant stirring of solution would have assured an even mix of the solute particles and a more accurate freezing point. These small errors could have affected both trials creating a higher observed molar mass value for both trials. Conclusion: The experiment allowed for the determination of freezing point of Cyclohexane based on a logger pro software with calibrated thermometers to be approximately 4.97ËšC (Table 1). Freezing point depression was observed when two trials of different concentration of the unknown solid were added to the Cyclohexane. As the concentration of the unknown solid increased, the freezing point of the solution was also lowered (Table 2). As seen on Figure 4, when placing all three graphs it is visible, when solute is added a lower freezing point is observed. Using experimental measurements, the molar mass of the unknown solid was calculated to be 286.87+1.796g/mol. Based on the relative standard deviation percent (%RSD) of 0.626%, shows a highly precise measurements of unknown solid molar mass when compared to the mean values.

King Lear - Disruption Of Order In King Lear And The Causes Essay

Shakespeare's King Lear is a play which shows the consequences of one man's decisions. The audience follows the main character, Lear, as he makes decisions that disrupt order in his Kingdom. When Lear surrenders all his power and land to his daughters as a reward for their demonstration of love towards him, the breakdown on order in evident. Lear's first mistake is to divide his Kingdom into three parts. A Kingdom is run best under one ruler as only one decision is made without contradiction. Another indication that order is disrupted is the separation of Lear's family. Lear's inability to control his anger causes him to banish his youngest daughter, Cordelia, and loyal servant, Kent. This foolish act causes Lear to become vulnerable to his other two daughters as they conspire against him. Lastly, the transfer of power from Lear to his eldest and middle daughter, Goneril and Regan, reveals disorder as a result of the division of the Kingdom. A Kingdom without order is a Kingdom in ch aos. When order is disrupted in King Lear, the audience witnesses chaotic events that Lear endures, eventually learning who truly loves him. At the start of the play, Lear decides to divide his Kingdom into three. Give me the map there. Know we have divided In three our Kingdom and ‘tis our fast intent to Shake all cares and business from our age. (I,i,37-39) This is the first indication that order is disrupted. Dividing up a Kingdom politically has many disadvantages that Lear do...

Essential Components of Effective Marketing Information System Essay

A marketing information system (MIS) is intended to bring together disparate items of data into a coherent body of information. An MIS is, as will shortly be seen, more than raw data or information suitable for the purposes of decision making. An MIS also provides methods for interpreting the information the MIS provides. Moreover, as Kotler’s1 definition says, an MIS is more than a system of data collection or a set of information technologies: A marketing information system is a continuing and interacting structure of people, equipment and procedures to gather, sort, analyse, evaluate, and distribute pertinent, timely and accurate information for use by marketing decision makers to improve their marketing planning, implementation, and control†. Figure below describes the major components of an MIS, the environmental factors monitored by the system and the types of marketing decision which the MIS seeks to underpin. The marketing information systems and its subsystems The explanation of this model of an MIS begins with a description of each of its four main constituent parts: the internal reporting systems, marketing research system, marketing intelligence system and marketing models. It is suggested that whilst the MIS varies in its degree of sophistication – with many in the industrialised countries being computerised and few in the developing countries being so – a fully fledged MIS should have these components, the methods (and technologies) of collection, storing, retrieving and processing data notwithstanding. Internal reporting systems: All enterprises which have been in operation for any period of time nave a wealth of information. However, this information often remains under-utilised because it is compartmentalised, either in the form of an individual entrepreneur or in the functional departments of larger businesses. That is, information is usually categorised according to its nature so that there are, for example, financial, production, manpower, marketing, stockholding and logistical data. Often the entrepreneur, or various personnel working in the functional departments holding these pieces of data, do not see how it could help decision makers in other functional areas. Similarly, decision makers can fail to appreciate how information from other functional areas might help them and therefore do not request it. The internal records that are of immediate value to marketing decisions are: orders received, stockholdings and sales invoices. These are but a few of the internal records that can be used by marketing managers, but even this small set of records is capable of generating a great deal of information.

Differences Of Shakespeare And Much Ado About Nothing By...

William Shakespeare was a well known British writer who was known for the many plays and sonnets he wrote. This 16th century writer wrote a play called Much Ado About Nothing in the year 1598 (Alchin). This play consists of many characters meddling into each others lives, causing chaos, lots of drama, and even romance making for some very comedic entertainment. The title gives away a lot about the plot that it really is a lot about nothing. Shakespeare is regarded as a very influential writer in British literature and has been an inspiration for literature beyond his time. This play has been recreated for the cinema in many versions of film. One version of film in particular is by the director Kenneth Branagh in 1993 (IMDb). Both the Much†¦show more content†¦There is two scenes in the film Much Ado About Nothing that there is actually live music played. The first scene is in the garden when Benedick is hiding trying to overhear Don Pedro, Leonato, and Claudio talk about how in love Beatrice is with Benedick. In the original play, the text says â€Å"[Enter BALTHASAR with Music]† as a stage cue (Shakespeare L.858). The second scene, is when Claudio is at the tomb of Hero saying his apology to her and praising her life. In the text, there is not a place that says â€Å"and now live music will be played for the characters to enjoy. This was most likely an effect added to the film for that grand effect. Especially because it shows how dedicated Claudio is to Hero and making it right. In the play, there also is a difference from the film. In Act five, Claudio is trying to make the slander he accused Hero right. Claudio is at Hero’s tomb, saying an epitaph to her: â€Å"Done to death by slanderous tongues Was the Hero that here lies.Death, in guerdon of her wrongs, Gives her fame which never dies. So the life that died with shame lives in death with glorious fame† (Shakespeare L. 2510). The play describes this happening early in the morning when the film has it in a scene that is pitch black outside, making it seem that it happened at night. The play and film of Much Ado About Nothing are bound to have differences but it’s nice toShow MoreRelatedWilliam Shakespeare s Much Ado About Nothing1285 Words   |  6 PagesMuch Ado About Nothing, is a comedic play by William Shakespeare thought to have been written in 1598 and 1599, as Shakespeare was approaching the middle of his career. (Wikipedia) This timeless play is generally considered one of Shakespeare’s best comedies, because it combines a cheerful mood with an intricate series of deceptions and miscommunications. It’s known for its hilarity, honor, shame and court politics. Shakespeare depicts different kinds of loving relationships- romantic love, familyRead MoreA Comparison Between the Plots of King Lear and Much Ado about Nothing910 Words   |  4 Pagesstatement to say that William Sh akespeare wrote some of the greatest plays of all time. This is accepted by everyone from high schoolers to experts as fact. But everyone is always wondering, what makes them great? Well, at the heart of every great Shakespeare play is a well written plot. But how can one man churn out all these plays he’s written, and still have new content in each one? Aren’t they all the same story to some extent? As Lindsay Smith writes, â€Å"Many Shakespeare plays, like most typicalRead More Much Ado About Nothing Essay: The Character of Don John1112 Words   |  5 PagesThe Character of Don John in Much Ado About Nothing  Ã‚     Ã‚   William Shakespeares Much Ado About Nothing is a comedy in which he uses one of his more peculiar villains. 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According to the views of the author, the perfect male soulmate possesses a loving heart ,and a weird attitude toward theirRead MoreEssay on Inconstancy in Shakespeares Much Ado About Nothing 1099 Words   |  5 PagesInconstancy in Shakespeare’s Much Ado About Nothing The Oxford English Dictionary (OED) explains inconstancy as the recurrent and generally unexpected or impulsive change from one condition to another. It is the state or quality of being inconstant and unfaithful by virtue of being undependable or deceitful. Set in Messina, Sicily, Shakespeare’s Much Ado About Nothing is a very popular play generally viewed as one of his happiest comedies and is often performed in theatres. However, the playfulnessRead MoreWilliam Shakespeare s Romeo And Juliet1591 Words   |  7 PagesShakespeare is a prominent figure present throughout history. His writing is credited as some of the most influential pieces written in English literature. Shakespeare was born in 1564 in England. 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