Absorbance of light by a transition metal complex investigation Essay Example for Free

Absorbance of light by a transition metal complex investigation Essay Introduction Commonly known as transition metals, d block elements have partially filled d sublevels in one or more of their oxidation states. It is in the first row of transition elements that the 3d sub-level is incomplete. These d block elements show certain characteristic properties such as multiple oxidation states, ability to form complex ions, coloured compounds and good catalytic properties. In terms of variable oxidation states, d block elements usually have a +2 oxidation number which corresponds to the loss of the two 4s electrons (as it is easier to lose the 4s electrons than the 3d electrons). Transition metals can have variable oxidation states because the ionization energies allow for up to two 3d electrons to be lost. Because transition metals are relatively small in size, the transition metal ions attract species that are rich in electrons ligands (neutral molecules or negative ions that contain non-bonding pair of electrons which when covalently bonded with and form complex ions. Because the d orbitals usually split up into two groups (high and low) in transition metal complex ions, the energy required to promote a d electron into the higher split level corresponds with a particular wavelength in the visible region, which is absorbed when light passes through the complex ion. Transition metal usually then exhibits the remaining energy/light the complementary colour. In this investigation, the different absorbance of these coloured solutions will be investigated by varying the number of moles of the transition metal in the solution. According to the Beer-Lambert law, absorbance is directly proportional to the concentration and that there is a logarithmic dependence between the absorbance and the concentration of the substance, this relationship is as shown in figure 1 and 2. In the graph representation of the Beer-Lambert law, the logarithmic relationship can evidently be seen as the concentration of the solution increases, the calibration curve becomes less linear and more flat. This is probably due to the saturation of colour of the solution. In addition, the graph also indicates that the relationship starts at the origin and is generally linear at lower concentrations. In this investigation, Nickel (II) Sulphate will be used as the transition metal and H2O will be used as the ligand. The complex ion formed will therefore be a hexaaquanickel(II) complex ion, Ni (H2O) 6 2+. It has a coordination number of 6 and is of an octahedral shape. (Microsoft Encarta, 2007) Aim To investigate how the concentration of hexaaquanickel(II) ions (Ni (H2O) 6 2+) in solution affects the absorbance of red light (660nm) by measuring it with a colorimeter. Hypothesis As the concentration of hexaaquanickel(II) ions increases, the absorbance of red light1 will also increase. This is so because as stated in the Beer-Lambert law, the absorbance of light is directly proportional to the concentration. Furthermore, as the concentration increases, there are more molecules of the complex ions within the solution to interact with the light that is being transmitted hence an increased absorbance at higher concentrations. In addition, despite the logarithmic relationship, I expect my data to show a linear relationship instead because the number of moles I am measuring red absorbance against is rather low (maximum 0.5 moles), so while it would be insufficient to see the clear logarithmic curve; the linear increase in the beginning would still be evident. Variables Independent Concentration of hexaaquanickel(II) ions (0.0313mol, 0.0625mol, 0.125mol, 0.250mol, 0.500mol) Dependent Absorbency of red light (660nm) Controlled Volume of solution (25cmà ¯Ã‚ ¿Ã‚ ½ per different mol solution) Equipment Method 1) Measure 6.57g of nickel sulphate with an electronic balance and place in a 250cmà ¯Ã‚ ¿Ã‚ ½ beaker 2) Measure 50cmà ¯Ã‚ ¿Ã‚ ½ of deionised water with 50cmà ¯Ã‚ ¿Ã‚ ½ measuring cylinder and pour into the 250cmà ¯Ã‚ ¿Ã‚ ½ beaker with the nickel sulphate to create a 0.5mol nickel sulphate solution 3) Mix the solution thoroughly with a glass stirring rod, make sure the solution is transparent (not murky) and no remnants of the nickel sulphate should be present in the solution 4) Label the five 50cmà ¯Ã‚ ¿Ã‚ ½ volumetric flasks: 0.03125mol, 0.0625mol, 0.125mol, 0.25mol and 0.5mol 5) Pipette 25cmà ¯Ã‚ ¿Ã‚ ½ of the previously made nickel sulphate solution from the 250cmà ¯Ã‚ ¿Ã‚ ½ beaker and place into volumetric flask labeled 0.5mol 6) Pipette another 25cmà ¯Ã‚ ¿Ã‚ ½ from the beaker and place into volumetric flask labeled 0.25mol 7) Measure and pipette 25cmà ¯Ã‚ ¿Ã‚ ½ of deionised water and add into 0.25mol 8) Mix thoroughly 9) Measure and pipette 25cmà ¯Ã‚ ¿Ã‚ ½ from 0.25mol and add into 0.125mol 10) Repeat steps 7 to 8 but add the water into 0.125mol 11) Measure and pipette 25cmà ¯Ã‚ ¿Ã‚ ½ from 0.125mol and add into 0.0625mol 12) Repeat step 10 but add into the water 0.0625mol 13) Measure and pipette 25cmà ¯Ã‚ ¿Ã‚ ½ from 0.0625mol and add into 0.0313 mol 14) Repeat step 10 but add into the water0.0313mol 15) Connect the PASPORT colorimeter to the computer 16) Select to measure red (660nm) absorbance 17) After all five solutions have been made, label five cuvettes the same labels as the volumetric flasks (place on lid, careful not to have any of the label on the cuvette itself) 18) Fill each labeled cuvette with its corresponding volumetric flask label with a dropper 19) Fill the remaining unlabeled cuvette with water 20) Place the cuvette with water into the colorimeter and press green button to calibrate, do not do anything until the green light switches off by itself 21) Place the cuvette labeled 0.03125mol into the colorimeter press start and stop after getting a constant reading 22) Record the data 23) Repeat steps 21-22 until all labeled cuvettes have been measured for red absorbance Data Table Concentration / mol dm-à ¯Ã‚ ¿Ã‚ ½ Red light (660nm) absorbance Uncertainties Uncertainties (cm3) Measuring cylinder à ¯Ã‚ ¿Ã‚ ½1.0cmà ¯Ã‚ ¿Ã‚ ½ Bulb pipette à ¯Ã‚ ¿Ã‚ ½0.06 cmà ¯Ã‚ ¿Ã‚ ½ Electronic weigh à ¯Ã‚ ¿Ã‚ ½0.01g Concentration (mol/dmà ¯Ã‚ ¿Ã‚ ½) Uncertainty Graphs Discussion and Conclusion It can be seen from the graph that there is a linear relationship between the amount of red light absorbed and the concentration of hexaaquanickel(II) ions. It can also be deduced that as the concentration increases, the red light absorption increases at twice the rate. However, it is interesting to note that the line of best fit does not start at the origin, but at (0, 0.0623) as the equation derived from the line of best fit states, suggesting that despite showing a clear linear trend, my data is precise but not accurate. This is possibly due to equipment imperfection, for example the cuvette, which will be discussed in the evaluation. However, it is still evident that, as stated in my hypothesis, as the concentration increases, the chances of light interacting with the complex ion molecules also increase, hence yielding a higher light (red, in this case) absorption. While it is true that the Beer-Lambert law states the relationship between concentration of a substance and its absorbency has a logarithmic relationship, my data is linear because the concentrations of my tested solutions were rather low, so if I were to continue my experiment and create more concentrated nickel sulphate solutions, I would expect to see the curve become non-linear as concentration increases because the solution will eventually become saturated. Therefore, in conclusion, my hypothesis corresponds with the results: the relationship between red absorbance and concentration of hexaaquanickel(II) ions is quite clear as the concentration increases, the red absorbance also increases. Evaluation One aspect I can improve my method is using the same cuvette and in the same direction each time for measuring all the different solutions, as it has been noted that the cuvettes we have been currently using are not perfectly constructed and may differ with the distance as light passes through. This will help improve the accuracy of the results and an important aspect to take into consideration, because also stated in the Beer-Lambert law, the length in which the light passes through also makes a difference in the absorption of light (the longer the container is, the more chances of light interacting with the molecules of the solution). Another aspect was in the preparing the different solutions, because I had diluted each solution using the same solutions from before, so the uncertainty of each would naturally continuously build up (final uncertainty of 4.31%) for example, if I had accidentally created a 0.052 mol nickel sulphate solution, then the next solution I diluted from that solution would not be 0.025 mol as intended. One way to see through this limitation is to perhaps prepare each solution separately to avoid a build up of uncertainties. In addition, another way to make this investigation more conclusive and detailed could be increasing the different amounts of concentration of the nickel sulphate solution, as I only had 5 different concentrations. Bibliography Clark, J. (2007). The Beer-Lambert law. In Absorption spectra. Retrieved January 15, 2008, from http://www.chemguide.co.uk/analysis/uvvisible/beerlambert.html Microsoft(r) Encarta(r) Online Encyclopedia. (2007). Complex. Retrieved January 17, 2008, from http://au.encarta.msn.com/encyclopedia_781538720/Complex.html Neuss, G. (2007). Determining the concentration of an element. In Chemistry course companion (p. 276). Oxford University Press. 1 Because nickel sulphate solution is green in colour, red light will be used to measure the absorbency of the solution as it is the complementary colour.

Personal Strengths and Weaknesses Essay -- essays research papers

Everyone is embedded with things that make them unique. As individuals we each bring soemthing new, creative, and different to the table. This brings to to discuss personal strengths and weaknessess within myself and my everyday living. Personal strengths are areas where we tend to excel, and seem to express above average. Personal Weaknesses to me are areas where we would like to excel but seem to still need improvement. If I can, let me share with you my strengths and weaknesses and see how they effect my everyday being.   Ã‚  Ã‚  Ã‚  Ã‚  Lets begin with my personal strengths. To me these are areas where I think I excel and have the most experience. Being an effective communicator is one of the best traits that I think a person can carry. Effective communication consists of being able to speak clearly and professionally, while being knowleadgeable at the same time. I also have to ensure that the message that is being communicated is easy to understand and that my message covers all the facts and pertinent information. Communication has become one of the key parts to being successful in work life and in my personal life. Communication is key to my marriage and any relationship that I build within a team, workplace, and even with my small child. Being an effective communicator is definetely a strong point for me. Possessing the skills to be a leader is also a bright area for me. I learned at an early age that I love to be in charge and that taking initiative to get things done has a very positive out look. Being that I have learned my limitations and what is best for me, I do better as a leader and not a follower. Being a leader takes an outgoing personality, and a person that loves to work an be around people. It also takes good decision making skills and the ability to work well under pressure sometimes. I am truly a people person and feel that I have the traits that it takes to lead a group to the moon if need be. Which leads me into being a team player. I believe that team work is always a great asset to any work or personal group and being a team player is one of my stronger attributes. Being a team player means being able to work well with others, to offer assistance to others in need, and to be very open to new ideas and other peoples opinions. Being a team player to me falls right into place with being a people person and being able to wo... ...d, the bad, and the indifferent I feel that overall I am a great person and that I have many great qualities. As with anyone I have areas that I would surely like to be stronger in but only time will tell. I am starting to realize that the only way that I can change my weaknesses into strong points is to accept the fact that I have troubles in these areas and that they need to be fixed. Observering how my behaviors and weaker points affect others and my lifestyle will help me to develop a plan to fix these weak points beneath the surface. I think that once a person sits back and evaluates what their personal strengths and weaknesses are then a positive self evaluation can be made. Just from putting this paper together I have evaluated some things about myself that I havent touched base with in a long time. A persons strengths and weaknesses help to make up who they are and no one person is alike. I think that it is always important to know who you are and what you are made of and what better way than to evaluate the things that you can attribute and also the things that you work on to possible make you a better person.   Ã‚  Ã‚  Ã‚  Ã‚     Ã‚  Ã‚  Ã‚  Ã‚  

American Beauty 2

American Beauty Jessica Jackson (Thompson) Interpersonal Communication Alfred Wilfong November 19th, 2011 I chose to watch the movie American Beauty. I have seen this movie previously, and enjoyed watching it again. An interpersonal conflict that I identified in the movie was between Kevin Spacey’s character Lester and his wife Carolyn, played by Annette Bening. In chapter nine of our text, Daniel Dana suggested four factors that must be present for a disagreement to be considered a conflict: two parties are interdependent, both parties blame the other, on or more of the parties are angry or emotionally upset, and the parties’ behaviors are affecting their relationship with each other and others. (Dana, 2011) Carolyn was very ambitious and Lester was having what one would call a mid-life crisis. They both had very poor communication skills. Given they were married they were interdependent, they blamed each other for any and all issues in their relationship, they were both angry, and their behaviors were not only affecting their relationship with one another, but their relationship with their teenage daughter, who seemed to loathe her parents. They both handled their conflict differently. Carolyn began to have an affair with a business rival. Lester, after black-mailing his boss, takes a job at a fast food joint, starts lifting weights, and obsesses over his daughter’s friend. As I stated earlier they did not communicate well with one another. At dinner if they weren’t yelling at each other they were speaking to each other at all. Outside of intense couples therapy they needed to work on empathizing with one another. Lester should have told his wife about being laid off, and they could have worked through that trial together. Carolyn should have never had an affair, and instead expressed her frustration with Lester and they could have worked through her frustrations, together. Their hostility and conflict was just growing in the movie. It never seemed to lessen. They had no positive feelings in their conflict as well. They usually responded to anger with anger or anger with silence. Lester, Carolyn, and their daughter need to communicate more effectively. They can do this by listening to one another needs, empathizing with one another, and responding effectively.

Economic Environment Essay

We aim to provide the public with an effective and cheap solution in cleaning their clothes. We carry this out with a Triple-Action Laundry detergent which has an anti-bacteria content that also leaves the clothes clean, good as new and scented. Target Market Our target consumers are between the ages of 11 and 60 who can wash clothes and are responsible in choosing laundry detergents to use (cited in Phil48Girl, 2010). Our customers are normally member of the household and wash their own clothes. We consider not only the mother but everybody who needs their clothes clean and fragrant without spending a lot. Direct Competitors There are several laundry detergent brand manufacturers. But, only some are real companies. There are solo individuals that are also marketing in small towns. However, our product will speak for itself as it is very effective, very gentle to clothes and with adorable scent. We will also apply a door-to-door marketing strategy to introduce our product directly to our customers that other companies haven’t tried before. Political-Legal Environment We will manage to prepare legal papers and permits allowing us to do our marketing and productions on each place to avoid illegal problems. Social-Cultural Environment Social Medias like TV and radio, as well as, social networking online using Facebook and Twitter will be used as leverage. Our customers are well exposed to such Medias. Economic Environment Our product is immune with the economic crisis as we are offering it in a very low cost. Our customers are flexible and not affected as they need our product regularly. Technological Environment Our productions are well supported with generators for incidental loss of electricity. We also maintain substitute equipments when the manufacturing system is down. Summary The above analysis is reasonably confident enough to enter the actual market. Introducing the Triple-Action Laundry detergent, that is very affordable in price. There is a maximum range of prospect consumers in the market as everybody needs our product. Strategic marketing will be imposed as the company aim to reach more customers by bringing the product directly to their homes. The company will maintain the brand name in legal processes and will reach more people through social Medias and computer technology. We are also flexible to adjust technically in terms of economic and technological problems once occured. The above is a list of actions which needs to be executed properly, as a marketing plan with no reverberation of tactical foundation is useless (cited in Wikipedia, 2010). Considering the analysis of the different environment in this report brings out what to do and what should not be done during the process. Careful manipulation and management requires cooperation and good leadership to accomplish the goal. References: More Business (2010, March 26) Sample Marketing Pla. March 26, 2010, from www. morebusiness. com/templates_worksheets/bplans/printpre. brc Phil48Girl (2010, March 26) How to Teach Your Children to Wash Clothes. March 26,2010 from http://www. ehow. com/how_4693877_teach-children-wash-clothes. html Wikipedia (2010, March 26) Marketing Plan. March 26,2010 from http://en. wikipedia. org/wiki/Marketing_plan

Comparison Between Two political parties in Chile (PPD; PS) essays

Comparison Between Two political parties in Chile (PPD; PS) essays This project is based upon comparing two contemporary parties to each other, and then to the parties of Chile in the XIXth century. But before one can start to study this aspect, they must answer the question: "What is a political party?" By dictionary definition, the reply is: "An established political group organized to promote and support its principles and candidates for public office." We agree with this statement. A party is a gathering of people to promote their ideals and wishes in the government. Every party has it's leader and members, and is constantly in a battle to achieve presidency over the country. To do this they must gather support fom the people, oftentimes presenting them with statements that say that the people's wishes will come true, should the party rise to power. This incentive, of course, makes people vote. This project begins by analyzing both parties, in all their aspects; and then goes on to compare them to each other. Finally, we compare these parties to the parties in XIXth century Chile. Description of the Parties Being Compared The main principle of this party is to employ all forms of socialism in all aspects of society; maintaining that they have upheld socialism for all of their existence. They state that capitalism is a vile way of ruling a country; that it places "egotistical and separatist" thoughts in the minds of the people who they govern. This party aims to use democracy as a method of uniting all the aspects of society, to give them all a fair right to speak. They quote: "La democracia, para los socialistas, es el sistema polà ­tico que debe asegurar la convivencia entre los diversos componentes de la sociedad e inducir, por tanto, al desarrollo de los valores de la solidaridad y de la participacin ciudadana en todas las esferas de la vida social." This party claims that the economy of Chile is quite inneficient. According to their figures, for every 5% increase in produ...

Human Resource Management Essay Example | Topics and Well Written Essays - 750 words - 7

Human Resource Management - Essay Example As such, job analysis can be termed to be a component of planning where jobs are studied and analyzed to know the requisite characteristics and nature of the job. With the help of this information, competent and suitable candidates can be employed on that particular job (Ostwald 2003). Jobs make positions, positions make occupations and occupations transform themselves into organizational structure. As such, job analysis is the building block of not only human resources function, but also organizational behavior, structure and planning (Fig.1). Planning, recruitment, training and appraisal- all other HRM activities directly stem out from job analysis. Job analysis is actually a comprehensive data collection technique where some data relates to the job specifications and other pertains to the individuals. Thus, number of employee, characteristics of employees, nature and mode of training and objective appraisal of employees can be done only on the basis of job analysis. Evaluation of job- with the help of job analysis, relative worth of jobs is ascertained which in turn helps in determining the base compensation and relevance of the job in the organization. This proves to be an important criterion of cost cutting and cost saving activity for a firm. Employee development- when both the specifications of job and the individuals handling the job are determined in advance, it becomes easier to benchmark the performance levels and analyze the gaps. Moreover, specific areas of gap can be figured out which can then be resolved by using employee counseling and training sessions. Safety measures- process of job analysis is applied in all kinds of jobs be it technical, clerical or managerial. Therefore, it extends a bit beneficial in technical jobs where use of tools, machinery and equipments can give rise to hazardous conditions and unhealthy workplace environment. Job analysis tries to do away with

WAS BARRY GOLDWATER MISREPRESENTED BY THE MEDIA Research Paper

WAS BARRY GOLDWATER MISREPRESENTED BY THE MEDIA - Research Paper Example Media uses this phenomenon and controls us in many ways, as to how we remember events and people, thus effectively shaping our opinions. The power of media to shape opinions has always been lucrative to politicians. Consequently what the media shows us may not be the reality as portrayals and images sometimes lie in the category of paid-content, which is of course unreliable. Great leaders and politicians have always been a target for the media’s strident and harsh remarks. Barry Goldwater, â€Å"a five-term U.S. senator from Arizona and a champion of conservatism whose 1964 presidential candidacy who launched a revolution within the Republican Party† (Barnes, â€Å"Barry Goldwater†), is one victim herein. During that era he was also known as Mr. Conservative for his articulate, blunt and charismatic approach in political dealings. Politicians and leaders all over the globe still admire him for his values and have set him as a benchmark for themselves. This resea rch paper aims to briefly show how and why the media misinterpreted Barry Goldwater. Liberals during the 60’s had left no stone unturned to term Barry Goldwater as a racist and to tarnish his image in public but Goldwater stood as a man of principle and courage. He fought back to each and every allegation that was pointed towards him. It might be not be an overstatement to suggest that he had more enemies than friends but despite this fact, his political career had always been applauded. And even at this present day, it remains as interesting as it was back in the 60’s. To begin with, the first thing that needs discussion is his presidential elections in 1964 in which he had to face a crushing defeat by 16 million votes from Lyndon B. Johnson. Many factors contributed towards this but the most important of all was the misrepresentation of Barry Goldwater’s persona by the liberals. Moreover, the assassination of John F. Kennedy also contributed to his defeat, as it was discovered that he has been shot dead by someone with a Goldwater sticker on his forehead. So heartbroken was Goldwater at that time that he gave out a blunt statement, which further added to his criticism, i.e. â€Å"This is a great country, where anybody can grow up to be president...except me† (â€Å"Barry Goldwater†). Liberals were the actual culprits who misinterpreted him through media but in actuality, he was a staunch conservative with strong and practical thoughts, which if implemented, could have out casted the liberals. In the presidential elections of 1964 he was stereotyped as a nuclear war monger by the media. This was reinforced again and again by airing a television ad where a child was shown picking daisies counting down each petal till it reached one and then an atomic bomb exploding into a mushroom cloud with an announcer announcing in the background that these are the stakes so better vote for Johnson. By using tactics such as these, Goldwate r was highly misrepresented. Initially the liberals termed him as a racist because they said that he was a segregationist who would not allow equality and would not give an equal standing to every individual in the country. It all began when he insisted that he would vote for the approval of 1964 civil rights act if and only if section 2 on equal employment opportunity was removed. From then onwards, started a battle of allegations and misperceptions. People started calling him racist. They were aware