Citric Acid Essay Example for Free

Citric Acid Essay Introduction Soft drinks contain acid and sugar. These substances contribute to tooth decay and therefore are a cause for concern. In the first part of the investigation well measure the acidity in blackcurrant juice. Labels on black currant juice drinks usually state citric acid is present in the drink, but it doesnt give you the amount of how much it contains. Dilutable soft drinks contain between 0. 15 2. 5% of citric acid research by The British Drinks Association and therefore the second part of the experiment would be to determine the concentrations of blackcurrant juice in the diluted samples. Investigation 1: Measure the acidity of the blackcurrant juice drink In order to measure the acidity of the blackcurrant juice, Ill titrate black current juice with 0. 1mol of sodium hydroxide and use a pH meter to measure its pH. Technique The technique of this experiment is titration. It is a method of chemical analysis, which is used to determine the volume of concentration needed to react with an unknown solution. Equipments needed for titration: Burette   Conical Flask   Clamp Technique of using titration method: The measurement on the burette (cm3) tells you how much solution you have poured into the substance. This is useful to find the amount of solution needed to balance with the substance. At the end of the burette, there is a small tap that allows you to control the amount of solution needed to pour into the substance. It is important to be accurate on the amount you want to put in. Therefore, right timing and quick reaction is the key skill to this experiment. There are two ways of measuring the pH: pH indicator and pH meter. pH Indicator: A pH indicator is a chemical compound. It shows the pH changes in the substance by changing its colour when added. Different indicators have different colour. They only change its colour when a certain pH is reached. pH meter: A pH meter is an electronic machine used to measure the pH in liquids. It has a special measuring probe called the glass electrode connected to the electronic meter. It will then measure and display the pH reading. Because the black current juice is darkly coloured, therefore pH indicator would not be the most suitable method for this experiment. Im going to use a pH meter for this experiment. The Science Many of the soft drinks contain acids. It is use to balance the sweetness of the sugar present in the drinks. Citric Acid is one of the most common acid uses in soft drinks. Soft drink Blackcurrant juice contains: Water, Sugar, Glucose Fructose Syrup (from wheat and maize), Blackcurrant Juice from Concentrate (4%), Citric Acid, Vitamin C, Preservatives (Sodium Benzoate, Sodium Bisulphate) and Colour (Anthocyanins) Citric Acid Citric Acid is an organic acid. We can find it from citrus fruits such as lemon and orange. It is added to soft drinks to create an acidic taste (sourness). Citric Acid also helps preserve drinks from micro-organism because of its acidity. Micro-organism can only grow and multiply in neutral condition. The reaction between Sodium Hydroxide and Citric acid: The following equation shows the reaction of whats happening during the neutralisation reaction between Citric Acid and Sodium Hydroxide: Citric Acid + Sodium Hydroxide Sodium citrate + Water C6H8O7 + 3NaOH C6H8O7Na3+ 3H2O From the equation above we have worked out 1 mole of citric acid reacts with 3 moles of sodium hydroxide (1:3 ratios). Graph Demonstration. Strong and Weak Acids Acids are vary in strength. The strength of an acid is based on the number of Hydrogen ions in the atom. Strong acids: Strong acids have a strong proclivity to donate Hydrogen+ ions. All of the strong acids such as hydrochloric acid, Sulphric acid and Nitric acid are all 100% ionised in water. This mean all the strong acid would dissolve the reaction is fully complete and no unreacted substance remains in the solution. Weak acids: Weak acids have a weak tendency to donate Hydrogen+ ions. The donation of hydrogen+ ions does not dissociate completely.

The Europeans Acceptance of Imperialism Essay -- Age of Imperialism

If we look at the world we live in today, we notice that it has changed dramatically over the years since the 1800’s. Many historical events from the past have changed the way we live today. It has turned our knowledge and our lifestyle into something so ordinary, that we are not even aware of it. For instance, our education system, since we were kids we were always taught to read the map a certain way so that when we grew up and started to draw and label the map of the world, we always put Europe in the center. Our teachings have taught us to view the world through such a Eurocentric perspective. Furthermore, it is important to understand that our ways of practicing various fundamentals of life regard the historical background we come from. In the past the European powers had an impact on majority of the world. These European powers adopted a policy of Imperialism. Imperialism is an act that takes place when one with greater dominance takes over another nation in order to co ntrol its economical, political cultural, industrial and social life. By adopting the policy of Imperialism, most of Europe held dominance over the majority of the world and for that reason the map is drawn that way, in order to show how superior Europe is than other nations, or so it is perceived to be. While talking about most of the European countries being the dominant nation, it is vital to understand that their superiority was achieved by their acceptance of the policy of Imperialism, and the factors that contributed in this were economic, political and religious causes. The European countries believed that by imperializing land it will give them more power and prestige than other countries. A belief that more nations they ruled over, the more powerf... ...2014. . "What are 5 main causes of imperialism?." - Yahoo Answers India. N.p., n.d. Web. 3 Mar. 2014. . "What is Imperialism." Party for Socialism and Liberation. Convio, n.d. Web. 3 Mar. 2014. . "Regents Prep Global History Imperialism: Introduction." [Regents Prep Global History] Imperialism: Introduction. N.p., n.d. Web. 2 Mar. 2014. . Books Cited Howarth, Tony, and Josh Brooman.Twentieth century history: the world since 1900. 2nd ed. London: Longman, 1987. Print. Lucas, Robert E.. Lectures on economic growth. Cambridge, Mass.: Harvard University Press, 2002. Print.

Absalom Absalom and Love Essay

Many of the novels we have read this semester contain prevailing themes that provide insight into American society. One of these themes that we have closely examined throughout the semester is a person’s right to love. Love is undoubtedly a powerful force in one’s life. As we have seen through our readings, however, this force is often obstructed by the need to conform to social standards. Whether or not a couple is ALLOWED to be in love says a lot about what is socially acceptable for that particular area and time period. Although love is technically a right given to all, American Literature shows how it is often denied by social standards and therefore ceases to exist. William Faulkner’s Absalom, Absalom! tells Rosa Coldfield’s version of how Thomas Sutpen was the demise of her and her family. As the story progresses, it becomes known that Thomas’s son, Henry, kills Charles Bon to prevent him from marrying his sister, Judith. One would infer that Henry’s reason for his desperate need to prevent their marriage was because Charles was their half-brother, and therefore their marriage would be considered incest. We come to find out, however, that this is not exactly the case. In Chapter 8, in response to whether or not Judith will marry Bon she says â€Å"Yes. I have decided. Brother or not, I have decided. I will. I will (283). † As the chapter progresses, however, Quentin and Shreve accept that â€Å"it’s the miscegenation, not the incest, which (they) can’t bear (285). †In this case, two socially unaccepted taboos prevent Judith from pursuing her relationship with Bon. The fact that it is worse in the eyes of her family that Judith may be marrying a man with black blood than a man who is her relative, however, says a lot about how strong racial prejudices were in the south during the 1800s. Judith’s right to love Bon is forcefully obstructed by social norms, and is a perfect example of Southern culture during that time period. Another instance of love being obstructed by social standards is seen in F.  Scott Fitzgerald’s Great Gatsby. Jay Gatsby, a resident of West Egg and a symbol of new wealth, falls in love with Daisy, a resident of East Egg and a symbol of established wealth. Daisy and her husband, Tom, are described to have lived in â€Å"†¦a rather distinguished secret society (17)† to which members of old money had often tried and failed to become a part of. Throughout the novel, it is clear that Daisy had married Tom for his â€Å"†¦person and his position (151)† rather than for love. Yet when Daisy finally accepts that she had never loved Tom and was currently in love with Gatsby, the class divides remain too prevalent for her to pursue a relationship with Gatsby. Tom quotes â€Å" Nowadays people begin by sneering at family life and family institutions, and next they’ll throw everything overboard and have intermarriage between black and white (130). † From this quote and the happenings throughout the novel, the force obstructing the relationship between Gatsby and Daisy is the social condemnation of new money marrying old money. The Great Gatsby shows how in our society, is often difficult for people of different economic backgrounds to pursue a relationship. T. S. Eliot’s The Love Song of J. Alfred Prufrock is an examination of a typical man’s psychological struggle to express himself emotionally and conform to social standards. Throughout the poem, the narrator shows insecurity in almost everything he does, fearing that his moves will be frowned upon. He says â€Å"There will be time, there will be time to prepare a face to meet the faces that you meet† and often asks â€Å"Do I dare?  Ã¢â‚¬  and thinks about what â€Å"they will say. † His insecurity prevails in an encounter with what seems to be a woman he loves. He seems afraid that the woman will deny him because of his balding hair and thin composure, and thinks about what he should say in order to impress the woman; â€Å"And how should I then presume? How should I begin? † In the end the narrator concludes that â€Å" It is impossible to say just what I mean,† and he drifts into a fairytale by the sea until â€Å"human voice wake us, and we drown. † Eliot’s poem is an example of a man’s love for a woman being obstructed by his own need to conform to what is socially acceptable of a man. He refuses to open up and share with the woman his feelings in fear that he will be mocked and denied. â€Å"The Love Song of Alfred Prufrock† shows the struggles of maintaining masculinity, and the fear a man has of loosing his composure. While the last stories had similar circumstances and outcomes, love doesn’t always have to be between a man and a woman, and social norms aren’t always successful at obstructing love’s powerful force. In Mark Twain’s Huckleberry Finn, the love shared between Huck and Jim leads to a powerful revelation in Huck’s life and a groundbreaking relationship considering the South’s intrusive social standards. When Huck begins his journey with Jim, he is overcome by an instilled guilt for assisting in the runaway of Miss Watson’s slave. Huck says â€Å" It would get all around, Huck Finn helped a nigger get to his freedom; and if I was to ever see anybody from that town again, I’d be ready to get down and lick his boots for shame (226). †As their adventure progresses, however, Huck begins to realize how much he enjoys Jim’s company, slave or not; â€Å" But somehow I couldn’t seem to strike no places to harden me against him, just the other kind (227). † Huck struggles internally with this realization, but cannot get over the feeling in his heart telling him to keep Jim around. Finally, Huck decides that he would not turn in Jim, and that he would go to Hell if that were what it meant. In this instance, Huck valiantly goes against what is socially acceptable, and the force of love prevails. Huck and Jim remain friends even though it is extremely frowned upon. Although love is a freedom, one can see how easily and often this freedom is taken away due to what is acceptable in the eyes of others. The circumstances involved in the obstruction of love shows a lot about the society in which these characters live, and the values held by the people who lived there.

What Is a Reversible Reaction

A reversible reaction is a chemical reaction where the reactants form products that, in turn, react together to give the reactants back.  Reversible reactions will reach an equilibrium point where the concentrations of the reactants and products will no longer change. A reversible reaction is denoted by a double arrow pointing both directions in a chemical equation. For example, a two reagent, two product equation would be written as A B ⇆ C D Notation Bidirectional harpoons or double arrows (⇆) should be used to indicate reversible reactions, with the double-sided arrow (↔) reserved for resonance structures, but online youll most likely encounter arrows in equations, simply because its easier to code. When you write on paper, the proper form is to use the harpoon or double arrow notation. Example of a Reversible Reaction Weak acids and bases may undergo reversible reactions. For example, carbonic acid and water react this way: H2CO3 (l)   H2O(l)  Ã¢â€¡Å' HCO−3 (aq)   H3O(aq) Another example of a reversible reaction is: N2O4 ⇆ 2 NO2 Two chemical reactions occur simultaneously: N2O4 → 2 NO2 2 NO2 → N2O4 Reversible reactions do not necessarily occur at the same rate in both directions, but they do lead to an equilibrium condition. If dynamic equilibrium occurs, the product of one reaction is forming at the same rate as it is used up for the reverse reaction. Equilibrium constants are calculated or provided to help determine how much reactant and product is formed. The equilibrium of a reversible reaction depends on the initial concentrations of the reactants and products and the equilibrium constant, K. How a Reversible Reaction Works Most reactions encountered in chemistry are irreversible reactions (or reversible, but with very little product converting back into reactant). For example, if you burn a piece of wood using the combustion reaction, you never see the ash spontaneously make new wood, do you? Yet, some reactions do reverse. How does this work? The answer has to do with the energy output of each reaction and that required for it to occur. In a reversible reaction, reacting molecules in a closed system collide with each other and use the energy to break chemical bonds and form new products. Enough energy is present in the system for the same process to occur with the products. Bonds are broken and new ones formed, that happen to result in the initial reactants. Fun Fact At one time, scientists believed all chemical reactions were irreversible reactions. In 1803, Berthollet proposed the idea of a reversible reaction after observing the formation of sodium carbonate crystals on the edge of a salt lake in Egypt. Berthollet believed excess salt in the lake pushed the formation of sodium carbonate, which could then react again to form sodium chloride and calcium carbonate: 2NaCl CaCO3  Ã¢â€¡â€  Na2CO3   CaCl2 Waage and Guldberg quantified Berthollets observation with the law of mass action that they proposed in 1864.