Investigation looking At the Speed of Reactions :: GCSE Chemistry Coursework Investigation

Investigation looking At the Speed of Reactions Introduction The aim of this experiment is to find out how a variable can affect the results from a scenario set up in scientific environment. The experiment is to see how a certain variable will affect the amount of Gas produced from a Calcium Carbonate and Hydrochloric Acid Reaction. The Science Calcium Carbonate is a generally white or colourless mineral that is translucent. When compressed or exposed to great heat the mineral binds together in small to large clumps forming calcium Carbonate Chips, however left in it's formed state it is powder, a chalk like substance. I could use either forms of the Calcium Carbonate for the experiment. Hydrochloric Acid, is a clear, colourless to slightly yellow liquid with a sharp, pungent and irritating odour. It is a strong highly corrosive acid, soluble in water and alcohol but insoluble in hydrocarbons. The reason I am using Calcium Carbonate and Hydrochloric Acid for my experiment is due to the reaction when they are put together. A fizzing reaction takes place letting loose Calcium Chloride, Carbon Dioxide and Water. Word Equation ============= Calcium carbonate + Hydrochloric Acid ===> Calcium Chloride + Water + Carbon Dioxide Symbol Equation =============== CaCO3 + 2 HCl ---> CaCl2 + H2O + CO2 Prediction My prediction is that if the concentration of the acid increases there will be an increase in output of Carbon Dioxide from the reaction for example the highest concentration produce the most gas in the given time. I used a preliminary test to help in the prediction. I went and prepared marble chips and concentrated acid we tried the experiment, the results was clear that as in a few seconds it was almost finished. When we used very dilute acid it took so long for it to react and the amount of bubbles were much less than the first one. By using the results I can make the prediction of that, the rate of reaction is affected by concentration. Hypothesis If the concentration of an acid increase than output of gas will also increase. When the acid has a high concentration that means in that solution, compared to a dilute one there are more particles available to react with therefore the amount of times they will collide with the each other is more. Factors ------- There are many different factors, which effect the rate of reaction. Below is most of the known factors which effect the rate of a reaction: 1. The size of the particles of a solid reactant 2. The concentration of the reactants solution 3. Temperature of experiment 4. Amount of time available for reaction 5. Amount of solid reactant 6. Amount of reactant solution Particle size The reaction between calcium carbonate and dilute hydrochloric acid is