Determine the average for each. The temperature of the acid was then measured using the thermometer and its reading noted. Materials: Coffee-cup calorimeter Thermometer 100ml-graduated cylinder Scoopula Electronic balance MgO powder Mg ribbon Sandpaper or emery paper 1. The probability of a reaction occurring would definitely decrease as the calorimeter and balance would be in close proximity of one another. Swirled the solution gently, recorded the temperature every 30s until reached the highest temperature Tf.
I would expect that any error that might have occurred happened during the transference from one cup to another. In the duration of these few minutes, Magnesium was prepared for reaction using the following two steps. Be sure your doc is accessible to those who will read your essay. This was due to the production of MgO which is white in color and since it is insoluble in water, it turns water milky. In part I, the ΔH of each individual reaction was obtained by performing each reaction inside a calorimeter. Since the maximum temperature reached by the solution of 15cm3 water has been determined to be 34.
As a result, the polymer begins to give off volatile gases reducers , which mixes with atmospheric oxygen oxidizer. The lid of the calorimeter was closed as quickly as possible to ensure that heat loss through convection currents was minimized. It may delete a post erroneously. The thermometer has some problem, which made the data not so accurate. If the standard enthalpy of the products is less than the standard enthalpy of the reactants, the standard enthalpy of reaction is negative. To overcome this common oxide problem, the strip should be sanded off of its oxide coating using a sand paper. As time went by, the solution was turning milky white.
Graph 4: Highest temperature reached in Part Y, Trial 2. Petri dishes are easy to clean and the amount of powder on it can be adjusted very easily because they are shallow. There were two holes on the lid of the calorimeter and one was being used for the thermometer, however the second, although very small, was left open. However, since our magnesium was coiled too tightly within the crucible, it did not burn for the entire 45 minutes of the lab, even when we added hydrochloric acid to speed up the reaction. A lot of gas is forming.
The top of the calorimeter could also be covered with aluminum, this would not only cover the holes but would secure the space under the lid so any heat that may escape would stay within the area due to the aluminum. Wear goggles during the experiment. This is because since different humans have different reaction times, it is important to ensure that the systematic error due to reaction time is the same and is not varying. Table 2: Apparatus required for the experiment. The total percentage deviation from the literature value was unimpressively large but at the same time, it should be taken into consideration that it is not possible to perform such experiments require much more sophisticated instruments that those readily available in the school lab.
Also since Magnesium has a negligible heat capacity, its heat capacity is not taken into consideration when calculating the heat released in the solution. The temperature of solution in every trial was recorded every five seconds. Reaction 1 Magnesium Oxide Step 2 Reaction 1 Magnesium Oxide Step 1 Background Things you will need! To determine the accuracy of the calculation we can determine the % error: As far as accuracy goes a percent error of 2. Usually the energy change takes the form of heat. Planning B: Refer to lab handout entitled, of Reaction for the Formation of Magnesium Oxide. Every five seconds, the reading on the thermometer was read as accurately as possible and noted.
I would expect that any error that might have occurred happened during the transference from one cup to another. Part A Mass of the Calorimeter + Room Temp Water g 48. Swirled the solution gently, recorded the temperature every 30s until reached the highest temperature Tf. To determine the accuracy of the calculation we can determine the % error: As far as accuracy goes a percent error of 2. Excess of distilled water To be used to wash the calorimeter before using it for the next trial. Magnesium Ribbon Safety: Done 1.
Settled up the coffee-cup calorimeter. That might be a useful step. If we know the mass of magnesium at the start, and the mass of magnesium oxide produced at the end, we can work out the mass of oxygen which has been combined with the magnesium. Clean the piece of magnesium ribbon with sandpaper, then coil it loosely around a pencil. The dependant variable will be the mass of Magnesium Oxide, this is a measured variable as the mass of oxygen can be calculated and will enable us to determine the formula for Magnesium Oxide. Scrub the magnesium strips with steel wool to clean out impurities.
The 15cm3 was measured using a burette to reduce the percentage uncertainty. The Enthalpy of Formation of Magnesium Carbonate By: Jessica Miller T. Compound A substance made up of two or more different types of atoms that have been joined bonded together. Element A pure substance made up of 1 type of atom. You are trying to find out the enthalpy of formation.