Involves and acid and a metal Essay Example for Free

Involves and acid and a metal Essay The Problem: To investigate one of the factors affecting the rate of reaction between a metal and an acid. Background Knowledge: The balanced equation for the reaction that takes place between magnesium and hydrochloric acid is: Mg + 2HCl == MgCl + Cl From this equation, we can already see that it involves and acid and a metal, therefore: Acid + metal == salt + hydrogen The ionisation equation of the hydrochloric acid is: HCl(aq) == H + Cl This experiment will demonstrate the breaking of bonds. Bonds break in order to allow certain atoms to re-arrange before the new bonds are formed. When magnesium reacts with the hydrochloric acid, a particle of this acid must collide with a particle of the magnesium with adequate energy in order to break the bonds between the magnesium and the hydrochloric acid. This is known as the Collision Theory. The collisions between the particles must collide more often and with more sufficient energy in order for the rate of reaction to increase. Although, not every collision produces a successful reaction as they require a certain amount of energy to break bonds. This is called activation energy. The rate of a chemical reaction refers to the speed at which it happens, and different metals react at various rates. The progress of a reaction can be measured by the rate of a formation of a product or by the decrease of reactants. There are four main factors that can be varied to affect the rate of reaction between magnesium and acid: 1. Surface area (of the reactants) 2. Concentration (of the reactant) 3. Temperature 4. The presence of a specific catalyst If the surface area were increased by using a magnesium powder, then the reaction would speed up, as there are more particles that are able to collide with the hydrochloric acid. The products of a reaction are formed as a result of the collisions between the reactant particles. Consequently, if the concentration of a solution is increased, collisions are more likely to occur. The more often the particles collide, the higher the chance that a reaction will take place. Subsequently, the rate of a chemical reaction increases if the concentration of the reactant is also increased. This is also because the rate is proportional to the concentration. E. g. Diagram to illustrate a high concentration and a low concentration: When the temperature at which the reaction is carried out is increased, the energy of the particles also increases. As a result of this, the particles move much faster allowing them to collide more often with other particles. Therefore, as there are more collisions and these collisions are more energetic, the rate of reaction increases. Catalysts are used to speed up a reaction. These biological catalysts are extremely specific, therefore only speed up certain reactions. Every chemical reaction taking place has an exclusive enzyme catalyst (an enzyme is a protein molecule produced in a living cell.) A catalyst will decrease the activation energy and forms an alternative path to help the collisions to be more successful. Safety: As I will be using glass conical flasks and burettes, I will be very careful when handling them in case I harm myself or others by dropping them. The hydrochloric acid is also corrosive, which means that it is able to eat away at materials that it is within contact with. Again, I should handle this carefully and ensure that there are no spillages. Water seems quite harmless, but if I spill any, it is possible that someone may skid or trip on it. For safety precautions, I will wear goggles and an overall and also tie my hair back. Method:   I will begin by attatching a plastic burette clamp to a clamp stand at a practical height to begin my experiment.   I will then fill my water tub approximately 1/2 full with water, and place it next to my clamp stand (so that the burette clamp is able to hole the burette above the tub. )   Next, I will fill my burette with tap water above 50cmi   and attach it to my clamp stand using the burette clamp. Very quickly, I will swiftly turn the burette upside down and speedily submerge it under the water. Afterwards, I will produce the solution of hydrochloric acid and water using separate measuring cylinders. I will remove the bung that is stopping the conical flask, and pour in the measurements of hydrochloric acid and water. I will then drop the magnesium ribbon (which will be cut using scissors), replace the bung and swirl the solution for a second, whilst starting the stop clock. I will take readings every 10 seconds. Diagram: Apparatus:   Burette   Delivery tube Clamp stand   Burette clamp   Magnesium tape   Distilled water   Stop clock   Conical flask Measuring cylinders (at least 2).