Sunday, March 22, 2020

Hydrogen Peroxide free essay sample

The same reaction is catalysed by the  enzyme  catalase, found in the  liver, whose main function in the body is the removal of toxic byproducts ofmetabolism  and the reduction of  oxidative stress. The decomposition occurs more rapidly in  alkali, so  acid  is often added as a stabilizer. The liberation of oxygen and energy in the decomposition has dangerous side-effects. Spilling high concentrations of hydrogen peroxide on a flammable substance can cause an immediate fire, which is further fueled by the oxygen released by the decomposing hydrogen peroxide. High test peroxide, or HTP (also called high-strength peroxide) must be stored in a suitable, vented container to prevent the buildup of oxygen gas, which would otherwise lead to the eventual rupture of the container. In the presence of certain catalysts, such as  Fe2+  or  Ti3+, the decomposition may take a different path, with  free radicals  such as HO · (hydroxyl) and HOO · (hydroperoxyl) being formed. We will write a custom essay sample on Hydrogen Peroxide or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page A combination of  H2O2  and  Fe2+  is known as  Fentons reagent. A common concentration for hydrogen peroxide is  20-volume, which means that, when 1 volume of hydrogen eroxide is decomposed, it produces 20 volumes of oxygen. A  20-volumeconcentration of hydrogen peroxide is equivalent to 1. 667  mol/dm3  (Molar solution) or about 6%. Redox reactions In acidic solutions,  H2O2  is one of the most powerful oxidizers known—stronger than  chlorine,  chlorine dioxide, and  potassium permanganate. Also, through catalysis,  H2O2  can be converted intohydroxyl radicals  (†¢OH), which are highly reactive. Oxidant/Reduced product| Oxidation  potential, V| Fluorine/Hydrogen fluoride| 3. 0| Ozone/Oxygen| 2. 1| Hydrogen peroxide/Water| 1. 8| Potassium permanganate/Manganese dioxide. Chlorine dioxide/HClO| 1. 5| Chlorine/Chloride| 1. 4| In aqueous solutions, hydrogen peroxide can oxidize or reduce a variety of inorganic ions. When it acts as a reducing agent,  oxygen  gas is also produced. In  acidic  solutions  Fe2+  is oxidized to  Fe3+  (hydrogen peroxide acting as an oxidizing agent), 2  Fe2+(aq) +  H2O2  + 2  H+(aq) 2  Fe3+(aq) + 2H2O(l) and  sulfite  (SO2? 3) is oxidized to  sulfate  (SO2? 4). However,  potassium permanganate  is reduced to  Mn2+  by acidic  H2O2. Under  alkaline  conditions, however, some of these reactions reverse; for example,  Mn2+  is oxidized to  Mn4+  (as  MnO2). Other examples of hydrogen peroxides action as a reducing agent are reaction with  sodium hypochlorite  or  potassium permanganate, which is a convenient method for preparing  oxygen  in the laboratory. NaOCl +  H2O2  Ã‚  O2  + NaCl +  H2O 2  KMnO4  + 3  H2O2   2  MnO2  + 2 KOH + 2  H2O  + 3  O2 Hydrogen peroxide is frequently used as an  oxidizing agent  in organic chemistry. One application is for the oxidation of  thioethers  to  sulfoxides. For example,  methyl phenyl sulfidecan be readily oxidized in high yield to  methyl phenyl sulfoxide: Ph? S? CH3  +  H2O2   Ph? S(O)? CH3  +  H2O Alkaline hydrogen peroxide is used for  epoxidation  of electron-deficient alkenes such as  acrylic acids, and also for oxidation of  alkylboranes  to  alcohols, the second step of  hydroboration-oxidation. Formation of peroxide compounds Hydrogen peroxide is a weak acid, and it can form  hydroperoxide  or  peroxide  salts  or derivatives of many metals. For example, on addition to an aqueous solution of  chromic acid  (CrO3) or acidic solutions of dichromate salts, it will form an unstable blue peroxide CrO(O2)2. In aqueous solution it rapidly decomposes to form oxygen gas and chromium salts. It can also produce peroxoanions by reaction with  anions; for example, reaction with  borax  leads to  sodium perborate, a bleach used in laundry detergents: Na2B4O7  + 4  H2O2  + 2 NaOH 2  Na2B2O4(OH)4  +  H2O H2O2  converts  carboxylic acids  (RCOOH) into peroxy acids (RCOOOH), which are themselves used as oxidizing agents. Hydrogen peroxide reacts with  acetone  to form  acetone peroxide, and it interacts with  ozone  to form  hydrogen trioxide, also known as  trioxidane. Reaction with  urea  produces  carbamide peroxide, used for whitening teeth. An acid-base adduct with  triphenylphosphine oxide  is a useful carrier for  H2O2  in some reactions. Alkalinity Hydrogen peroxide can still form adducts with very strong acids. The  superacid  HF/SbF5  forms unstable compounds containing the  [H3O2]+  ion. Domestic uses * Diluted  H2O2  (between 3% and 8%) is used to bleach human  hair  when mixed with  ammonium hydroxide, hence the phrase peroxide blonde. * It is absorbed by  skin  upon contact and creates a local skin  capillary  embolism  that appears as a temporary whitening of the skin. * It is used to whiten  bones  that are to be put on display. 3%  H2O2  is effective at treating fresh (red) blood-stains in clothing and on other items. It must be applied to clothing before blood stains can be accidentally set with heated water. Cold water and soap are then used to remove the peroxide treated  blood. Some horticulturalists and users of  hydroponics  advocate the use of weak hydrogen peroxide solution in watering solutions. Its spontaneous decomposition releases oxygen that enhances a plants root development and helps to treat  root rot  (cellular root death due to lack of oxygen) and a variety of other pests. Laboratory tests conducted by fish culturists in recent years have demonstrated that common household hydrogen peroxide can be used safely to provide oxygen for small fish. Hydrogen peroxide releases oxygen by decomposition when it is exposed to  catalysts  such as  manganese dioxide. * Hydrogen peroxide is a strong oxidizer effective in controlling sulfide and organic-related odors in wastewater collection and treatment systems. It is typically applied to a wastewater system where there is a retention time of 30 minutes to 5 hours before hydrogen sulfide is released.

Thursday, March 5, 2020

Overview of the U.S. Quasi-War With France

Overview of the U.S. Quasi-War With France An undeclared war between the United States and France, the Quasi-War was the result of disagreements over treaties and Americas status as a neutral in the Wars of the French Revolution. Fought entirely at sea, the Quasi-War was largely a success for the fledgling US Navy as its vessels captured numerous French privateers and warships, while only losing one of its vessels. By late 1800, attitudes in France shifted and hostilities were concluded by the Treaty of Mortefontaine. Dates The Quasi-War was officially fought from July 7, 1798, until the signing of the Treaty of Mortefontaine on September 30, 1800. French privateers had been preying on American shipping for several years prior to the beginning of the conflict. Causes Principle among the causes of the Quasi-War was the signing of the Jay Treaty between the United States and Great Britain in 1794. Largely designed by Secretary of the Treasury Alexander Hamilton, the treaty sought to resolve outstanding issues between the United States and Great Britain some of which had roots in the 1783 Treaty of Paris that had ended the American Revolution. Among the treatys provisions was a call for British troops to depart from frontier forts in the Northwest Territory which had remained occupied when state courts in the United States interfered the repayment of debts to Great Britain. Additionally, the treaty called for the two nations to seek arbitration regarding arguments over other outstanding debts as well as the American-Canadian border. The Jay Treaty also provided the United States limited trading rights with British colonies in the Caribbean in exchange for restrictions on the American export of cotton.  Ã‚   While largely a commercial agreement, the French viewed the treaty as a violation of the 1778 Treaty of Alliance with the American colonists. This feeling was enhanced by the perception that the United States was favoring Britain, despite having declared neutrality in the ongoing conflict between the two nations. Shortly after the Jay Treaty took effect, the French began seizing American ships trading with Britain and, in 1796, refused to accept the new US minister in Paris. Another contributing factor was the United States refusing to continue repaying debts accrued during the American Revolution. This action was defended with the argument that the loans had been taken from the French monarchy and not the new French First Republic. As Louis XVI had been deposed and then executed in 1793, the United States argued that the loans were effectively null and void. The XYZ Affair Tensions heightened in April 1798, when President John Adams reported to Congress on the XYZ Affair. The previous year, in an attempt to prevent war, Adams sent a delegation consisting of Charles Cotesworth Pinckney, Elbridge Gerry, and John Marshall to Paris to negotiate peace between the two nations. Upon arriving in France, the delegation was told by three French agents, referred to in reports as X (Baron Jean-Conrad Hottinguer), Y (Pierre Bellamy), and Z (Lucien Hauteval), that in order to speak to Foreign Minister Charles Maurice de Talleyrand, they would have to pay a large bribe, provide a loan for the French war effort, and Adams would have to apologize for anti-French statements. Though such demands were common in European diplomacy, the Americans found them offensive and refused to comply.  Informal communications continued but failed to alter the situation as the Americans refused to pay with Pinckney exclaiming  No, no, not a sixpence! Unable to further advance their cause, Pinckney and Marshall departed France in April 1798 while Gerry followed a short time later. Active Operations Begin Announcement of the XYZ Affair unleashed a wave of anti-French sentiment across the country. Though Adams had hoped to contain the response, he was soon faced with loud calls from the Federalists for a declaration of war. Across the aisle, the  Democratic-Republicans, led by Vice President Thomas Jefferson, who had generally favored closer relations with France, were left without an effective counter-argument. Though Adams resisted calls for war, he was authorized by Congress to expand the Navy as French privateers continued to capture American merchant ships. On July 7, 1798, Congress rescinded all treaties with France and the US Navy was ordered to seek out and destroy French warships and privateers operating against American commerce. Consisting of approximately thirty ships, the US Navy began patrols along the southern coast and throughout the Caribbean. Success came quickly, with USS Delaware (20 guns) capturing the privateer La Croyable (14) off New Jersey on July 7. The War at Sea As over 300 American merchantmen had been captured by the French in the previous two years, the US Navy protected convoys and searched for the French. Over the next two years, American vessels posted an incredible record against enemy privateers and warships. During the conflict, USS Enterprise (12) captured eight privateers and liberated eleven American merchant ships, while USS Experiment (12) had similar success. On May 11, 1800, Commodore Silas Talbot, aboard USS Constitution (44), ordered his men to cut out a privateer from Puerto Plata. Led by Lt. Isaac Hull, the sailors took the ship and spiked the guns in the fort.  That October, USS Boston (32) defeated and captured the corvette Berceau (22) off Guadeloupe.  Unknown to the ships commanders, the conflict had already ended.  Due to this fact, Berceau was later returned to the French. Truxtun the Frigate USS Constellation The two most noteworthy battles of the conflict involved the 38-gun frigate USS Constellation (38). Commanded by Thomas Truxtun, Constellation sighted the 36-gun French frigate LInsurgente (40) on February 9, 1799. The French ship closed to board, but Truxtun used Constellations superior speed to maneuver away, raking LInsurgente with fire. After a brief fight, Captain M. Barreaut surrendered his ship to Truxtun. Almost a year later, on February 2, 1800, Constellation encountered the 52-gun frigate, La Vengeance. Fighting a five-hour battle at night, the French ship was pummeled but was able to escape in the darkness. The One American Loss During the entire conflict, the US Navy only lost one warship to enemy action. This was the captured privateer schooner La Croyable which had been purchased into the service and renamed USS Retaliation. Sailing with USS Montezuma (20) and USS Norfolk (18), Retaliation was ordered to patrol the West Indies. On November 20, 1798, while its consorts were away on a chase, Retaliation was overtaken by the French frigates LInsurgente and Volontaire (40). Badly outgunned, the schooners commander, Lieutenant William Bainbridge, had no choice but to surrender. After being captured, Bainbridge aided in Montezuma and Norfolks escape by convincing  the enemy that the two American ships were too powerful for the French frigates. The ship was recaptured the following June by USS Merrimack (28). Peace In late 1800, the independent operations of the US Navy and the British Royal Navy were able to force a reduction in the activities of French privateers and warships. This coupled with changing attitudes in the French revolutionary government, opened the door for renewed negotiations. This soon saw Adams dispatch William Vans Murray, Oliver Ellsworth, and William Richardson Davie to France with orders to commence talks. Signed on September 30, 1800, the resulting Treaty of Mortefontaine ended hostilities between the US and France, as well as terminated all previous agreements and established trade ties between the nations. During the course of the fighting, the new US Navy captured 85 French privateers, while losing approximately 2,000 merchant vessels.