How can we speed up the reaction between Calcium Carbonate and Hydrochloric Acid? Contents 1. Plan ? Aim ? Equipment ? Variable Factors ? Prediction ? Method ? Trial Run 2. Results ? Results Tables 3. Analysis and Conclusions ? Graphs ? Conclusions 4. Evaluation ? Accuracy Of Results ? Reliability ? Improvements ? Extending the Investigation 1. Plan Aim I am doing this experiment to find out how I can speed up the reaction rate between calcium carbonate and hydrochloric acid. Equipment This is the equipment I will use: ? Gas Syringe ? Glass Flask ? Calcium Carbonate ? Hydrochloric Acid.
Variable Factors The factors that could slow down or speed up this reaction are: ? The size of the Calcium Carbonate (marble) pieces ? This will affect how fast the acid reacts with the marble, the smaller the pieces, the bigger the surface area so the reaction can take place faster. ? The amount of Calcium Carbonate ? The more calcium carbonate there is, the more carbon dioxide will be produced and the larger the reaction will be. ? The amount of Hydrochloric Acid ? The more hydrochloric acid there is, the more carbon dioxide will be produced and the larger the reaction will be.?
The temperature of the materials ? The temperature of the materials determines how fast the reaction will take place. The hotter the materials, the faster the reaction and vice-versa. ? The concentration of Hydrochloric Acid ? The higher the concentration (strength) of the acid, the faster it will react. ? The purity of the Calcium Carbonate pieces ? The purity of the calcium carbonate will affect the speed of the reaction also. Prediction From previous experiments I have learned that if large pieces are broken into smaller pieces they react faster because they have more surface area.
This is because at the molecular level, there are more molecules at the surface of the chips for the molecules of acid to react with when the chips are broken into smaller pieces. The same principle can be applied to the marble chips. The smaller the chips the more surface area so I predict that the smaller marble chips will react faster than the larger chips. Method Here is the set up: In this experiment I will be keeping the variables I mentioned earlier the same except one to keep the experiment fair. I will be changing the size of the marble chips to see which size reacts the fastest.
The gas syringe is firstly clamped to the stand and a plastic tube and bung are attached to the syringe. The marble chips are then measured out (I will be using 2g of marble chips each time) and the hydrochloric acid (10ml) is added to the flask. The chips are then added and the bung is quickly placed over the flask to create an airtight seal. The amount of carbon dioxide in the gas syringe is read off every 10 seconds until the reaction stops or the gas syringe runs out of capacity (100ml). Risk Assessment Goggles must be worn at all times to prevent acid going in eyes.
Gas syringes must be handled with care to prevent accidents Variables Table Dependant VariableValueHow Measured Amount of carbon dioxide collectedAmount read every 10 seconds. 2 repeats for each size of marble chipGas syringe and digital stopwatch Independant Variable Size of marble chipsPowder, small, medium and large chips prepared by teacher. 2g used each time. Size measured by third party. Weighed using digital scales. Control Variables Amount of acid10ml each timeMeasuring Cylinder Concentration of acid1 molar acidMeasured by third party. TemperatureRoom temp. Approx 27? CN/A.
Purity of calcium carbonateAssumed the same puritySame batch used each time Trial Run Time(sec)Powder (ml of CO )Small (ml of CO )Medium (ml of CO )Large (ml of CO ) 1044782 206813102 307924232 409129322 5010035392 6042472 7053532 8061612 9070672 10079722 11084752 120100802 130842 140892 150932 160972 1701002 These trial run results helped me with my final method 2. Results Time (sec)Amount of Carbon Dioxide (ml) Powder (ml of CO )Small (ml of CO )Medium (ml of CO )Large (ml of CO ) 105975810111453 2073921416172153 3083962124233053 40921003034303853 501004044364653 605053425553.
705962496253 806971556953 907678627453 1008486678253 1109192728653 1209798769153 130100100809753 1408510053 1509053 1609553 1709753 18010053 Control variables Amount of Hydrochloric Acid = 10ml Amount of Calcium Carbonate = 2g Temperature = Approx. 27? C Acid Concentration = 1 molar 3. Analysis and Conclusions Graphs Conclusion By looking at the results table and the graph, I am able to prove my predictions correct. The smaller the size of marble chip, the faster it will react with the acid. This is because there is a bigger surface area meaning a larger surface for the acid to react with.
The large marble chips in my experiment only reacted with the acid on the outside of the chip and there was unreacted marble inside because the acid couldn’t reach it. As the marble chips got larger, the reaction with acid was slowed until the size of the chips reached a point where they only reacted with the outside of the marble. I think once it gets to this point, it does not matter about the size of the marble chips anymore because they will only react with the surface of the marble and not penetrate the inside. 5. Evaluation Accuracy of results There is always some degree of inaccuracy in any experiment.
I think that there were several factors in my experiment that made the results slightly inaccurate. These were; ? The time taken to place the bung on the flask ? This let out a small amount of carbon dioxide into the atmosphere instead of the gas syringe. ? Weighing and measuring inaccuracy’s ? The weighing of the marble chips will always be slightly inaccurate due to the scales inaccuracy. This is the same with the measuring of acid. ? The size of the marble chips ? The size of the marble chips was not always the same, some were larger or smaller than others. This would have made for a slight inaccuracy.
Reliability
No significant problems or difficulties were encountered when carrying out this experiment. The accuracy and reliability of the results and conclusions are very good. Even though I have outlined the inaccuracy’s of the experiment, these are only t be expected and do not have much impact on the overall conclusion. Improvements The procedure used was simple and straightforward and not many difficulties were encountered. One difficulty was that the gas syringe was subject to humidity which made the syringe move not as smoothly as it would have otherwise. A small improvement could be made to the method of mixing the marble and acid as a small amount of gas was wasted when securing the bung onto the flask.
There could also be slight improvements made with respects to the accuracy of the equipment used. Extending the investigation If I had wanted to investigate further, I would have changed the different control variables to see which combonation gave the fastest reaction time. I would of also tried different sizes of chips measured exactly with a bigger range of sizes. It would also be interesting to add a catalyst to the reaction or to use a different atmosphere in the flask such as nitrogen or helium.