Water Hardness Essay Example for Free

Water Hardness Essay METHODS: 1. Prepare an approximate 0.004 M disodium EDTA solution. To prepare this solution, weigh about 0.7-0.8 g of Na2EDTA and dissolve in 500 mL deionized water in your plastic bottle. Make to to shake the bottle to dissolve the salt. 2. Obtain a 250-mL Erlenmeyer flask and transfer a 10 mL of CaCO3 using a buret into the flask. 3. Measure 30 mL of deionized water and add it into the titration flask. 4. Make sure to stir the solution 5. Inside a fume hood, add 3mL of ammonia/ammonium chloride buffer (pH10) into the flask and stir for another 30 seconds. 6. Add four drops of Eriorchrome Black T indicator solution. Stir for another 30 seconds 7. Begin titration. Record your initial volume and final volume. At the endpoint, the color will change to pink to violet to blue. 8. Repeat this titration two more times. Now that you recorded the volume, your second and third trial should be a lot easier. 9. Take your water sample that you obtain from the stockroom and record the unknown number. 10. Transfer 25 mL of the unknown water sample to a 250-mL Erlenmeyer flask. 11. Add about 20 mL of deionized water to the titration flask. Stir for 30 seconds 12. Inside a fume hood, add about 3 mL of ammonia/ammonium chloride buffer (pH10) and stir for another 30 seconds. 13. Add four drops of Eriorchrome Black T indicator solution to your flask and stir for 30 seconds. 14. Begin titrating. Record you initial volume and final volume. Repeat this twice more. Calculate the average hardness and your experimental precision from the three trials. RESULTS: EDTA Solution: 0.7533g of Na2EDTA mixed with 500ml DI water Table A: Standardization of EDTA Trial| Start Volume| End Volume| Amount of EDTA| 1| 3.90ml| 29.85ml| 25.95ml| 2| 5.35ml| 28.35ml| 23.00ml| 3| 0.45ml| 23.50ml| 23.05ml| Moles EDTA calculations 1st and 3rd trial (10.1 mL CaCO3) x (1L/1000ml) x 1.000g CaCO3/1L) x (1 mole CaCO3/100.1 g CaCO3) x (1 mole EDTA / 1 mole CaCO3) x (1000ml/L) = 0.101moles EDTA/L 2nd trial (9.90 ml CaCO3) x (1L/1000mL) x (1.00 g CaCO3/L) x (1 mole CaCO3/100.1g CaCO3) x (1 mole EDTA/1 mole CaCO3)x (1000 mL/1L) == 0.099 moles EDTA/L Mean molarity: (0.101 + 0.099 + 0.101)/3 = 0.100 moles EDTA / L Water hardness calculations Unknown water sample #24 Table 2. Water sample Trial| EDTA | Water sample #24| 1| 13.45ml| 25.1ml| 2| 13.35ml| 25.5ml| 3| 13.50ml| 25.0ml| CaCO3 molar mass: 100.1g/mole 1st trial (13.45 mL EDTA/25 mL of unknown water sample) x (1L/1000mL) x (0.101 moles EDTA/1L) x (1mole CaCO3/1 mole EDTA) x (100.1 g CaCO3/1 mole) x (1000 mg CaCO3/1g) x (1000mL/1L) == 5439.2 mg CaCO3/1L 2nd trial (13.35 mL EDTA/25 mL of unknown water sample) x (1L/1000mL) x (0.099 moles EDTA/1L) x (1mole CaCO3/1 mole EDTA) x (100.1 g CaCO3/1 mole) x (1000 mg CaCO3/1g) x (1000mL/1L) == 5291.9 mg CaCO3/1L 3rd trial (13.50 mL EDTA/25 mL of unknown water sample) x (1L/1000mL) x (0.101 moles EDTA/1L) x (1mole CaCO3/1 mole EDTA) x (100.1 g CaCO3/1 mole) x (1000 mg CaCO3/1g) x (1000mL/1L) == 5459.5 mg CaCO3/1L Calculate the total hardness in ppm CaCO3 1st trial 13.45ml EDTA x (0.004M/1000ml) x (100.1g CaCO3/1mole CaCO3) x (1000mg CaCO3/1g CaCO3) x (1000L/25.1ml) = 214.6 ppm CaCO3 2nd trial 13.35ml EDTA x (0.004M/1000ml) x (100.1g CaCO3/1mole CaCO3) x (1000mg CaCO3/1g CaCO3) x (1000L/25.5ml) = 209.6 ppm CaCO3 3rd trial 13.50ml EDTA x (0.004M/1000ml) x (100.1g CaCO3/1mole CaCO3) x (1000mg CaCO3/1g CaCO3) x (1000L/25ml) = 216.2 ppm CaCO3 Average ppm (216.2 + 209.6 + 214.6)/3 = 213.5ppm CONCLUSION: The concentration was concluded to be 213.5 ppm in the unknown which is right about in between Phoenix’ water hardness which is 164-291 ppm. REFERENCE: Department of Chemistry.(2012,February).Complexometric Determination of Water Hardness.Mesa Arizona City of Phoenix Official Website http://phoenix.gov/waterservices/quality/index.html

Hepatitis B Virus Essays -- Essays Paper

Hepatitis B Virus Characteristics: Hepatitis B Virus (HBV) is a double-stranded DNA virus in the Hepadnaviridae family. The infectious particle is 42nm in diameter, with a genome 3200 nucleotides long. It has an outer envelope and an icosahedral nucleocapsid, which contains viral DNA polymerase and has a diameter of 27nm. The envelope contains the HBV surface antigen (HBsAg); this is the molecule to which anti-HBV antibodies are directed. The non-infectious hepatitis B particles are composed of HBsAg only and come in the form of filaments and spheres. Their only likely purpose is binding up antibodies so the infectious particles can remain free. In humans HBV infects hepatocytes where it replicates within the nucleus, but can also be found in smooth muscle, bone marrow, kidneys, thyroid glands and other sites. Infection: HBV is usually transmitted from blood to blood and can be contracted via infected needles (IV drugs and tattoos), sexual contact, cuts, hemodialysis, vertical transmission at birth and blood transfusions. In developed countries blood is screened for the presence of HBsAg before transfusion. Unlike other forms of viral hepatitis, HBV cannot be transmitted by contaminated food or water. The CDC states that preventive measures for HBV infection are similar to those for HIV. Diagnosis of HBV can be made by the presence of HBsAg, which can be found in the serum a few weeks before onset of illness. The anti-HBsAg antibody is found weeks to months after infection and can last, in some cases giving life-long immunity. Hepatitis B is found mostly in Africa, Southeast Asia, Indonesia, the Philippines, and parts of the Caribbean. In those areas all socioeconomic groups are af... ...d/slide_1.htm http://www.nlm.nih.gov/medlineplus/ency/article/003243.htm http://www.merck.com/pubs/mmanual/section4/chapter47/47c.htm http://www.globalserve.net/~harlequin/HBV/hbvcore.htm http://www.globalserve.net/~harlequin/HBV/hbvx.htm http://www.globalserve.net/~harlequin/HBV/hbsags.htm http://www.foodallergy.org/anaphylaxis.html http://www.cdc.gov/mmwr/preview/mmwrhtml/00033405.htm http://depts.washington.edu/druginfo/Vaccine/HealthDept/ImmuneGlobulin.html http://www.livertransplant.org/livernewsletterselectingcandidatesforlivertransplantation.html http://www.ias.org.nz/hepatitis_b_vaccine.htm http://yourlawyer.com/practice/overview.htm?topic=Hepatitis%20B%20Vaccine http://www.comeunity.com/adoption/health/hepatitis/hep_photo2.html http://www.ncbi.nlm.nih.gov/ICTVdb/Images/Safrica/hbvcore3.htm http://livertransplant.org/

The Role of Government and the Relationship Between the Individual and the State

Lara O’Gorman The legacy of an empire is defined by its ability to conquer and make a mark on society. Many people throughout history sought to create empires as a way to establish their power. Often when one looks at the wide spectrum of history, some empires only last a few hundred of years and then dwindle out. After their fall, their legacy does not continue and their history is loss to the ages. Without a legacy, Rome would have ceased to exist, and would not have carried it’s ideals to post-classical civilizations.Rome had a successful and functioning government that help established its power, grandeur, and impressive knowledge of the arts. Within society it is vital to have a dependable and structured government as to prevent uproar and rebellion. The importance of a stable and powerful government is portrayed in the literary work Lord of the Flies and the idealization of political rulers and the subordination of subjects is conveyed through the art pieces the B ronze Statue of the Emperor Trebonianus Gallus and the Marble Portrait of Marcus Aurelius.Rome is remembered as a vast empire that stood above all surrounding civilizations with pride and honor. Rome, at it’s highest point, was thought of as immortal and impenetrable. It was only until the gradual decay of the empire that people thought of it as mortal. Before the detrimental rippling stages of the fall of Rome, powerful rulers and structured government was instilled within the empire. Several of these powerful emperors kept Rome under their rule by subordinating their subjects and by enforcing political unity. Other rulers used tolerance and active roles in society to appeal to their subjects.One ruler, Marcus Aurelius ascended to the throne in 161 AD and was deemed a philosopher king that was different from his predecessors. His philosopher status is recorded through the common depiction of him in a toga and adorning a Greek-inspired beard. He was interested in rational thi nking and tolerated all different sects of religion. Some say that his openness was his downfall and that his optimistic view of all things caused him to allow one of Rome’s worst emperors into his line of heir. Aurelius had an active role in government and did not discriminate against lower class people moving up in the world.He allowed people that were fit for government job, no matter what class, to have a say. This demonstrates his thought on his subordinates and how he not afraid to converse and involve himself with them. His openness is reflected in the calm and composed face of the portrait and how he is wise and is making a noble decision. Marcus was a fierce ruler and a good general, despite Rome’s loss against the Germanic tribes in war. The toga in which is realistically draped over his torso can be interpreted as a general’s attire. The militaristic style of his clothing suggest that he is the protector and is a strong ruler.Marcus lived a life of lu xury and suffered little. His wealth enabled him to surround himself with items of luxury. The emperor of Rome usually had portrait busts of their ancestors within his palace, which communicates the important and high position Marcus Aurelius had within society. The portrait busts were usually idealized, which can be see in the flawless bust that communicates that Marcus Aurelius was a strong, intelligent, and wealthy ruler. A second ruler, whom in contrast used his power and authority to rule his subordinates, ascended to power after the death of Decius in 251 AD at the battle of Abrittus.There, Trebonianus Gallus took on the position of ruling the vast and expansionist civilization of Rome. The troops that Decius led claimed Trebonianus Gallus a suitable ruler due to his familiarity with the government and his influence as a senate member. Gallus, to prevent the Goths from attacking again, signed a peace treaty that stated he would pay yearly tribute to them. To demonstrate Gallus ’ power over his subjects and ability to make executive decisions, the bronze statue portrays his arm are outstretched. This gesture is common with giving commands and looking down upon subjects from a higher point in society.Once Gallus was instated as emperor, he found that his empire had become plague stricken and the Roman population was dropping. To gain admiration from his subjects he buried the dead plague victims properly and spared no expense. This action suggests a confident personality, which is further expressed in the facial expression. Gallus, however, was seen inept in all other political categories. He was indecisive about detrimental political decisions, which greatly affected the state. Due to Gallus’ lack of political leadership, rebellions sparked within the empire, causing Trebonianus to flee to the north with his troops.The facial expression of the statue could also be interpreted as oblivious to his political duties and to the betrayal he would s oon face. With the threat of defeat and possible death lingering over his army, Gallus was killed, along with his co-emperors. Trebonianus Gallus was not seen as a beneficial addition to the empire and caused a plethora of problems, along with a growing feeling of discontent within the empire. The lack of skills Trebonianus possessed called for the end of his life. Although Gallus lacked military skill, his statue portrait is portrayed with the hair and beard style that soldiers favored.This conveys how leaders were idealized as to express authority and the greatness of the empire. When the leader of a united group becomes corrupt and unfit to complete his role in government, the subjects take action into their own hands. If discontent rises, rebellion and removal of power are probable. The mutiny that occurred with the homocide of Gallus, greatly demonstrates the importance of having a competent and understanding ruler as well as how the state is strong enough to react to problems that greatly affect the state as a whole.The fall of the great Roman Empire can be credited to many factors, but what caused the empire to completely corrode was the invasion by barbarians. In 410 AD, the Visigoths were led by Alaric to Ravenna where they soon ransacked the city and caused Rome to finally surrender its title of immortal. Due to the empire being strained prior to the attacks because of corruption in government, loss of tradition, and an unskilled military, it was easy for Alaric to fulfill the prophecy of penetrating â€Å"the city. It was clear that after the invasion by the Visigoths, Rome would not come out of it alive and victorious. The lack of a stable and prosperous government was one of the main factors that enabled Alaric to conquer Rome, which conveys the vitality of a strong government head. Compared to the fall of Rome, the plot of the Lord of the Flies by William Golding further explains why it is essential to have a central authority and how lacking th is political aspect can cause the downfall of a civilization.The 1954 novel discusses the social perils that ensue amongst English school boys once authority is not there to advise them. The literary work commences with the introduction of a tall blonde boy named Ralph that is soon accompanied by the voice of reason known as Piggy. During the time it takes Piggy and Ralph to become acquainted, they both realize that there are no adults on the island where their plane has crashed. They are astonished by this information but they still ask the question â€Å"Aren’t there any grownups at all? † The only reply that can be uttered is â€Å"I don’t think so. At first this information excited them and they become full of independence zeal, but later throughout the novel they begin to realize that a stable figure head is needed in order to have society function properly. Within society on the island, order is centered around a conch shell. This shell has symbolic value of order, normality, and power. Whomever holds the shell has the power to speak and to be heard. Piggy finds the shell within the first couple of stages of the plot and Ralph eventually uses it to signal the other children that were spread around the island by the crash.When all the children gather round the conch, a political issue arises; Who will be leader? Between the two most influential people in the group, Ralph and the chorus leader, Jack, an election is held. To Ralph’s advantage, the children say â€Å"Let him be chief with the trumpet thing. † The children recognize the conch as a centralizing factor and they search for stability in their new lives on the island. As with most empires and groups, irrational actions and discontent began to grow due to fear, anger, and power struggles. Power is wanted by the chorus leader, Jack, who sees himself as the most capable leader.He wishes to be in control, so he seeks the most controlling role within the new society; a hunter. By being the leader of the hunting party, he controls life and death and to whom or what he damages. The fact that Jack becomes this strong blood-thirsty leader enables the group to break away and form a corrupt and independent kingdom on the island. Strife begins to arise and violent actions begin to break out as the quest for power comes to a head. One of the most dramatic scenes in the book is when Ralph and Piggy go to Jack’s fortress in search of peace and unity.This peaceful venture turns into a bloodbath when the conch is destroyed and Piggy is killed by a boulder that is pushed from a mountainside by a chaos-consumed boy named Roger. Piggy was trying to remind the boys of the importance of rescue and how unity and peace should exist between the boys, but due to the lack of a strong and noble government, chaos and violence rules the kingdom of Castle Rock. The conch was the only remaining symbol of unity and stability, and it was crushed under the weight of a rock, which symbolically can be interpreted as the pressures of society and pure bedlam in society.The dark side of man is portrayed in the actions of the boys at Castle Rock. Because of these actions, â€Å"Ralph wept for the end of innocence, the darkness of man’s heart, and the fall through the air of a true, wise friend called Piggy. † At this point in the novel, society is out of control and unorganized. The perils of man and the way society becomes tumultuous and coercive communicates the need for a stable head of government. For without a functioning government, chaos is able to run rampant and disorganization can spread wildly. Government helps to instill organization and keeps the people at peace of mind.The government makes corporal decisions that are usually for keeping social rebellions at ease and to keep daily lives functioning. History demonstrates these points, whether it be through the art works or the literary works, but still manage to communicate the ideals and power of the ruler of the time. Whether it be for a demonstration of power or a depiction of what society is like when not controlled, the purpose of the portrayals is to call for the use of a stable government in order to make a legacy for the empire in which the ruler has sovereignty.

A Study On Molecular Studies - 1517 Words

Cyclopropenyl cation (1), the smallest hydrocarbon molecule is a centro-symmetric molecule with a D_3h symmetry. It’s the simplest aromatic species demonstrating aromatic features linked to the delocalization of the two Ï€ electrons. It follows the Hà ¼ckel’s rule, (4n+2) Ï€ electron with n = 0. Aromaticity cannot directly be experimentally measured. However, various methods were performed such as computational studies from the Schleyer group^1, which address the energy, structural changes and magnetic properties of cyclic conjugated system. Computational studies were performed using the Gaussian 94 computational package with ab initio method and the complete basis set amended by Peterson and co-workers was used for calculations.^2 The†¦show more content†¦Ã£â‚¬â€"ã€â€"(CH)ã€â€"_3ã€â€"^++cyclopropane →cyclopropyl cation (1) Reaction Different substituents have different effects on the stability of 1. Effect of these substituents were studied on the relative stability of 1. Either these substituents have an electron withdrawing effect or electron donating effect on the ring. Electron withdrawing group such as trialkylsilyl groups attached directly to the carbenium ion centre have a destabilizing effect. However, tris(trimethylsilyl)cyclopropenylium hexachloroantimonate (2) could be synthesize from readily available materials as shown in figure 2 and it’s relatively stable.^4 As shown in figure 3, C-C bond lengths for the tris(trimethylsilyl)cyclopropenylium cation are not equal. The ring is significantly distorted from its ideal D_3h symmetry since one of the carbon atoms in the ring system is close to the chlorine atoms in the hexachloroantimonate. This distortion shows that it is caused by the counterion and lattice effects.^4 Using the isodesmic hydride transfer reaction, the effect of trisilyl and trismethyl substitution was calculated. Three sillyl groups stabilize 1 by 22.4 kcal/mol while three methyl groups has a larger effect and more stable than 1 by 31.4 kcal/mol. Thus, Me Si H was found as the order of the