Rates Of Reaction :: essays research papers

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  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  =   Ã‚  Ã‚  Ã‚  Ã‚  MgCl2 +   Ã‚  Ã‚  Ã‚  Ã‚  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 â€Å"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   Ã‚  Ã‚  Ã‚  Ã‚  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 â€Å"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