...- Planning Hypothesis I predict that as the temperature increases, the speed of the reaction will increase therefore the gas will be produced faster. I believe this because most chemical reactions happen faster when the temperature is higher. At higher temperatures molecules mover around faster, which makes it easier for them to react together. Usually, rises of 100C will double the rate of reaction. Chemical reactions take place by chance. Particles need to collide with enough velocity so that they react. As the temperature is increased the particles move faster since they have more energy. This means that they are colliding more often and more of the collisions have enough velocity to cause a reaction. Since there are more collisions the chemical reaction takes place faster. Pilot Experiment To decide on the best volume and concentration of hydrochloric acid and best mass of magnesium a number of calculations were done and a pilot experiment conducted. The equation for the reaction is: Magnesium(s) + Hydrochloric Acid(l) Magnesium Chloride(l) + Hydrogen(g) Mg(s) + 2HCL(l) MgCl2(l) + H2(g) We were advised to use 0.1g of magnesium ribbon (found to be 10.9 cm long). The Relative Molecular Mass (RMM) of magnesium is 24, therefore the moles of magnesium to be used was: Moles= 0.1 24 Moles= 0.00416 In the reaction above, 1 mole of magnesium reacts with 2 moles of hydrochloric acid. The concentration of acid was 1mol/dm3. Therefore the volume of hydrochloric acid used was: Volume = 0.00416 * 2 1 Volume = 0.0083dm3 Volume = 8.3cm3 It was decided to use an excess of hydrochloric acid to ensure all the magnesium reacted, therefore 10cm3 of acid was used in the pilot experiment. At room temperature 10cm3 of hydrochloric acid was added to 0.1g of magnesium and the gas was collected (see fig 1). The volume of gas produced was measured every 15 seconds....
