Prediction
I predict that the warmer or hotter the reactant (In this case Hydrochloric acid) is, the quicker the reaction between the marble and the acid will take place. I think this because the more heat is applied, the more energy the molecules of the Hydrochloric Acid will have, therefore making the reaction occur much faster.
Method
Apparatus List
●Basin filled with tap water
●Burette
●Conical Flask with side arm and bung
●G-Clamp with Stand
●Marble (Calcium Carbonate)
●2.5m Hydrochloric Acid
●Thermometer
●Bunsen Burner
●Tripod, Gauze and Heat-Proof Mat
Diagram of Apparatus
We weighed out the Marble into groups weighing 1g and then put them to the side. We then turned the Bunsen burner on and heated up the acid in the conical flask until it was at the desired temperature. We decided to test the reactivity at 40˚C, 50˚C, 60˚C, 70˚C, 80˚C, 90˚C and 100˚C. We filled the burette up to 50cm3 and then turned it upside down with our hand over the end. We filled the basin half full with tap water and placed the burette upside down in the water, and then removed our hand. We used the G-Clamp to hold the burette in position just off the bottom of the basin. When the Acid was heated to the desired temperature we took it of the tripod and place the end of the sidearm into the bottom of the burette. We dropped the marble into the conical flask containing the acid and quickly placed the bung on the top. We then timed how long it took for the carbon dioxide being produced to be pumped into the burette and force all of the water out using a timer.
Results
There was a big decrease in the time taken to produce 50cc of carbon dioxide between 40˚C and 50˚C. After that there was a slow and fairly steady decrease in the time taken to produce 50cc of Carbon Dioxide.
Conclusion
The reaction rate between the amylase and the hydrogen pyroxide increased as the temperature was increased because this gave the Hydrochloric Acid molecules more energy, so a greater percentage of the collisions between Calcium Carbonate molecules and the Hydrochloric Acid molecules produced reactions than at lower temperatures. This agrees with my prediction, as the time taken to empty the burette of water decreased with higher temperatures.
Evaluation
I feel we could have improved our results by doing lower temperature acid, to produce moòe accurate results. This would help as we could test the time taken to produce 50cc of Carbon Dioxide at room temperature, and even at much colder temperatures. We also could have done intermediate temperatures between our existing temperatures, such as doing a test every 5˚C, e.g.20˚C, 25˚C, 30˚C, 35˚C and so on until 100˚C. If we had been able to keep the acid at the acquired temperature this would have made our results even more accurate, as the acid probably dropped greatly in temperature as the reaction was taking place.
