heat of formation of mgo lab report

Mass of Calorimeter (g)1.79 It This is just a sample. will fizz vigorously, so be careful. Specific heat capacity is the quantity of heat needed to raise the temperature per unit mass. Mg (s)    DH2  Enthalpy formation is the amount of heat needed to produce one mole of a substance, from its elements in standard state. The development of MgO from magnesium and oxygen is very exothermic and is in this manner hard to quantify legitimately. 0000044487 00000 n This lab only requires the following sections of the notebook and report Cite this article as: William Anderson (Schoolworkhelper Editorial Team), "Heat of Reaction for the Formation of Magnesium Oxide Lab Answers," in. its elements in their standard states. Also, The standard enthalpy of formation is defined as the enthalpy of formation measured at 1 atm such that the elements are in their standard state. Your online site for school work help and homework help. +    2 H+ (aq) << MgO is small, white granular pieces, a fine white powder. 4. the calorimeter, and the temperature change of the solution: Energy Mass of HCL (g)101.76 To determine the heat formation of MgO (Magnesium Oxide) using Hess’s Law, which states the heat within a chemical reaction is independent of the pathway between the initial and final states. of water one degree Celsius.   Privacy enthalpy changes for the component reactions. 0000047996 00000 n 0000056890 00000 n An energy transfer will occur between the reacting species and the 0000005029 00000 n Data Analysis: Therefore, the average temperature high for the MgO and HCl solution in trial 1 was 30.0⁰C. 7. Feel the solution getting hotter while conducting experiment. Again, collect temperature data until calculation, show the algebraic summation of component reactions and enthalpy +    2 H+ (aq) 0000020951 00000 n solution is plotted as a function of time. Direct measurement requires the use of complex trailer solution in which the reaction takes place. 2. 66 0 obj Essay, Use multiple resourses when assembling your essay, Get help form professional writers when not sure you can do it yourself, Use Plagiarism Checker to double check your essay, Do not copy and paste free to download essays. By knowing (x) we could then calculate the heat of reaction for Mg with HCl (ΔHA kJ/mol) and for HCl with MgO (ΔHB kJ/mol) using the equation q=m(HCl+X)C ΔT where m is the mass of the reactant used with Mg + X, C is the heat capacity of water (4.184 J/g°C), and ΔT is the total temperature change in each reaction. instant of mixing of the reactants) the true maximum temperature, Tf, is known, the energy transferred during the reaction can be calculated using the specific heat capacity of the solution, the mass of solution (solid + HCl) in the change in enthalpy for the overall reaction will be equal to the sum of the Consequently, this would have led to a decrease in the mass of the magnesium, one that would have been unknown at the time. Since it is difficult to measure the enthalpy of combustion of a metal directly, in this lab it will be determined indirectly by applying Hess’s Law of Heat Summation. 3. The electronic balance, or any balance, should be placed at the work station and as soon as the right amount of magnesium has been measured out it should be poured into the calorimeter immediately. In this experiment we will measure the amount of heat released from 3 reactions (ΔHA ΔHB ΔHC) and calculate the sum of all 3 reactions to determine ΔHT, which will give us the heat formation of MgO. Therefore the discrepancies in the experiment, however small, could have led to a lower value than expected which resulted in the low percent error. By continuing we’ll assume you’re on board with our cookie policy, Your Deadline is Too Short? Let Professional Writer Help You, 6000 Fairview Road, SouthPark Towers, Suite 1200, Charlotte, NC 28210, USA. lab. The energy which would be When this temperature change is multiplied by the heat capacity, the amount of heat needed to raise the temperature of a body by one degree, we can measure the change in converting our initial components (reactants) to their respective products. One of the problems which is encountered in measuring temperature /Metadata 34 0 R For example, the standard enthalpy of formation of magnesium oxide Chem 212 Lab 5: Enthalpy of Formation of Magnesium endobj I would expect that any error that might have occurred happened during the transference from one cup to another. Then using mathematical formulas we were able to calculate the heat formation of MgO, which is measured in kJ/Mol. Mg (s)    states that if a reaction can be regarded as the sum of two or more reactions, Place the beaker on a stirrer/hotplate. (3). To determine the heat formation of MgO (Magnesium Oxide) using Hess’s Law, which states the heat within a chemical reaction is independent of the pathway between the initial and final states. Therefore, the average temperature high for the MgO and HCl solution in trial 1 was 46.0⁰C. (2016, Aug 08). (aq)    +    H2O (l) Final temperature of HCl + Mg (°C)42.0 %%EOF Mass of Mg (g)0.5 of the two trials in Part A. Mass of HCl (g)99.88 We use cookies to give you the best experience possible. Although this does not completely stop heat from escaping it certainly decreases the amount that can escape. Very exothermic. According to the textbook, the accepted value for ΔHT=-601.8 kJ/mol. 0000047549 00000 n What’s more, is that the lid was not as tight as it could have been since it simply snapped on to the container being used as a calorimeter and was not air tight, which also could have let some heat escape. Enthalpy of Formation of Magnesium Oxide Calorimetry . 0000006677 00000 n Mg is small grey chunks like little shiny stones. is the energy transferred in the formation of one mole of magnesium oxide from The new solution is clear and odourless despite the previous odour of the HCl. To then calculate the heat formation of MgO ΔHT, the sum of all the reactions must be determined including ΔHC, the heat formation of water, which is already predetermined to be -285.8 kJ/mol. Because the methods of the experiment were conducted using a crude calorimeter I would have expected the percent error to be higher, assuming that because of it’s construction it would not have very high efficiency. %���� Feel the solution getting a lot hotter while conducting the experiment. Therefore, the following equations can be used to find the enthalpy of MgO (s): Mg (s) + 2HCl (aq) MgCl 2 (aq) + H 2 (g) ΔH B = ? is known, the energy transferred during the reaction can be calculated using the /Info 33 0 R Because the substances were transferred so quickly and taking into account the number of seconds that it took to replace the thermometer to begin recording data again it is possible that energy was either lost in the transfer or energy was lost before the recording was actually able to begin. The loss of energy to the surroundings cannot be Science Teacher and Lover of Essays. The heat To calculate X using the equation [m(h2o)+X]Cwater+Δwater=-1(m(ice water)CwaterΔtice water) the variable X must be isolated and doing so we were than able to calculate the correction factor: Based on the calculations of the calorimeter correction factor, X was determined to be 0.158 g. Then using the equation q=m(HCl+X)C *ΔT, where q is equal to the amount of energy given off, and than calculating the value in -kJ/Mol (because these are exothermic reactions) we were able to determine ΔHA and ΔHB. Calculation of H f for magnesium oxide For your calculated values of H 1 and H 2, find the mean value and range for each. Calculate the mean 0000017889 00000 n state from its elements in their standard states is referred to as the standard assume that the density of the HCl solution is 1.00 g/mL unless Though through the observation of changes in other aspects of. equipment and is therefore not practical in the first year laboratory. I'm not sure if I did something wrong during the experiment or if I'm doing something wrong with the calculations but the answer I'm getting for delta H(formatio) MgO is 154 kJ/mol which is nothing like the accepted value of -601.8 kJ/mol. Heat of Formation of Magnesium Oxide. ® As per lab manual we used a calibrated calorimeter (using a rounded end thermometer so as to not puncture a hole in the calorimeter) to determine the heats of reaction for Magnesium (Mg) with Hydrochloric Acid (HCl) and Hydrochloric Acid with Magnesium Oxide (MgO). In this lab we were able to determine the heat of formation of MgO using a simply constructed calorimeter, which was found to be -618.35 kJ/mol. This is just a sample. DH1. In this lab we were able to determine the heat of formation of MgO using a simply constructed calorimeter, which was found to be -618.35 kJ/mol. assumption is made that all energy transfer is in the form of heat. Chemical reactions require heat energy to complete, called an endothermic reaction, or produce heat energy, and thus called an exothermic reaction. Using a graduated cylinder, measure out 100.00-mL of the HCl solution created in the step above into the Styrofoam cup. Remember. 0000047743 00000 n There is a very strong and bad odour. typed in the usual fashion.