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Term Papers on Rates Of Reaction
Rates of Reaction BACKGROUND INFORMATION What affects the rate of reaction? 1) The surface area of the magnesium. 2) The temperature of the reaction. 3) Concentration of the hydrochloric acid. 4) Presence of a catalyst. In the experiment we use hydrochloric acid which reacts with the magnesium to form magnesium chloride. The hydrogen ions give hydrochloric acid its acidic properties, so that all solutions of hydrogen chloride and water have a sour taste; corrode active metals, forming metal chlorides and hydrogen; turn litmus red; neutralise alkalis; and react with salts of weak acids, forming chlorides and the weak acids. Magnesium, symbol Mg, silvery white metallic element that is relatively unreactive. In group 2 (or IIa) of the periodic table, magnesium is one of the alkaline earth metals. The atomic number of magnesium is 12. Magnesium(s) + Hydrochloric acid(aq) = Magnesium Chloride(aq) + Hydrogen(g) Mg + 2HCl = MgCl2 + H2 In the reaction when the magnesium hits the acid when dropped in, it fisses and then disappears giving of hydrogen as it fisses and it leaves behind a solution of hydrogen chloride. The activation energy of a particle is increased with heat. The particles which have to have the activation energy are those particles which are moving, in the case of magnesium and hydrochloric acid, it is the hydrochloric acid particles which have to have the activation energy because they are the ones that are moving and bombarding the magnesium particles to produce magnesium chloride. The rate at which all reactions happen are different. An example of a fast reaction is an explosion, and an example of a slow reaction is rusting. In any reaction, reactants chemical reactions® products. We can measure reactions in two ways: 1) Continuous:- Start the experiment and watch it happen; you can use a computer “logging” system to monitor it. I.e. Watching a colour fade or increase. 2) Discontinuous:- Do the experiments and take readings/ samples from the experiment at different times, then analyse the readings/samples to see how many reactants and products are used up/ produced. Reaction rate = amount of reactant used up time taken If the amount used up is the same each time then the only thing that changes is the time taken. so, reaction rate µ 1 time taken. rate = K time taken. Where K is the constant for the reaction. For particles to react:- a) They have to collide with each other. b) They need a certain amount of energy to break down the bonds of the particles and form new ones. This energy is called the “Activation Energy” or Ea. When we increase the temperature we give the particles more energy which: 1) Makes them move faster which In turn makes them collide with each other more often. 2) Increases the average amount of energy particles have so more particles have the “activation energy” Both of these changes make the rate of reaction go up so we see a decrease in the amount of time taken for the reaction and an increase in time taken. = 1 Time taken reflects the rate of reaction. Because temperature has an effect on both the speeds at which the particles react and the activation energy they have a greater effect on the rate of reaction than other changes. A change in concentration is a change in the number of particles in a given volume. If we increase the volume:-a) The particles are more crowded so they collide more often. b) Although the average amount of energy possessed by a particle does not change, there are more particles with each amount of energy;- more particles with the activation energy. a) is a major effect which effects the rate, but b) is a minor effect which effects the rate very slightly. In this experiment we are not concerned with whether the reaction is exothermic or endothermic because we are concerned with the activation energy needed to start and continue the reac... This is ONLY a preview of the article. If you would like to view the entire document, you must subscribe to Digital Term Papers. Please register below now! Digital Term Papers has over 63,000 essays, term papers, and book notes online. Many paper sites will charge you hundreds of dollars for a single paper. Digital Term Papers only charges $14.95 for a one month membership with instant account activation! Don't waste anymore time! Join NOW!!!
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