hess law lab report | Observational Error | Mole (Unit)

 

hess law experiment lab report

E12F-1 Experiment 12F FV 10/1/10 CALORIMETRY AND HESS’S LAW: FINDING ΔH FOR THE COMBUSTION OF MAGNESIUM MATERIALS: 12 oz. Styrofoam cup with lid, thermometer, mL and mL graduated cylinders, weighing boat, M HCl, M NaOH, magnesium ribbon, magnesium oxide, copper wire. Nov 16,  · Liam Weinert. Hess Law Experiment. November 16, Background Information: The purpose of the performed experiment was to prove Hess Law through the use of calorimetery and to determine the standard enthalpy of formation of magnesium oxide through the use of the reactants magnesium, magnesium oxide and hydrochloric acid Calorimetery is an extremely accurate process /5(15). View Notes - Lab Report - Calorimetry and Hess' Law from CHEMISTRY at John Carroll University. Abstract: The main purpose of this experiment is to find the heat produced in four91%(33).


Hess' Law Lab | Enthalpy | Chemical Reactions


Aim: To determine the enthalpy change for the decomposition of sodium hydrogen carbonate into sodium carbonate. Introduction In this experiment, Hess Law will be used to determine the enthalpy change for the decomposition of sodium hydrogen carbonate into sodium carbonate. This will be done by conducting two experiments shown below. By manipulating these two equations shown above to form the target equation shown below of the decomposition of sodium hydrogen carbonate, this thus allows for the determination of the enthalpy change as specied in the aim.

Calculation: Equation required:! H products -! H reaction a [! Value Literature Value of the Enthalpy Change! H reactants! The purpose of providing the information above is solely to indicate where the uncertainties for the measurements and calculations shown in the Data Collection and Data Processing stages is derived from.

Data Collection Note that trials refer to the trials conducted for Experiment 1 and trials A-C refer to the trials conducted for Experiment 2. Note that the 50 ml of acid is assumed to be equal 50 grams of acid this is assumed because the density and specic heat capacity of HCl is similar to water and 1ml of water is equal to 1g.

The duration of each trial has been kept constant and so limited to 1 minute. Bubbles also started to form, indicating a chemical reaction was taking place and that a gas was being formed as a hess law experiment lab report product. Furthermore, the temperature of the styrofoam cup in which the reaction was taking place in increased as we felt the cup getting hotter.

Indication of an exothermic reaction taking place. Note that the 50 ml of acid is assumed to be equal 50 grams of acid this is assumed because the density and specic heat capacity of HCl is similar to water. Furthermore, the temperature of the styrofoam cup in which the reaction was taking place in increased as we felt the cup getting cooler.

Indication of an endothermic reaction taking place. Chemistry Avinash Bharwaney 3 Data Processing i. T [Table 4] Average Temperature Change!

There is no uncertainty for this value. H of Experiment 1 using! T [Table 2] Average Temperature Change! Hess Law Calculation Equations: 1. This is because the target equation has 2NaHCO 3.

Reverse the rst equation. When you reverse the equation, note that the "H is multiplied by hess law experiment lab report Cancel out these two equations to form the target equation, hess law experiment lab report.

Calculate the enthalpy values in the process, hess law experiment lab report. This could be because of the heat lost due to the poor insulation of the styrofoam cup. Each reaction resulted in a change in temperature! Tmeasured in kJ. This was the only primary data collected and is shown on Table 2 for Experiment 1 and Table 4 for Experiment 2. There is a clear difference between the two values, suggesting that the method used in the experiment to collect the primary data, the heat energy change data, may have proved to be futile.

To calculate the temperature change of the reaction of either experimenta styrofoam cup was used as the calorimeter. The main purpose of a calorimeter is to maintain the the heat energy within a system and keep the system closed, since heat energy can easily disperse into the hess law experiment lab report environment if not insulated properly.

Using a styrofoam cup as the calorimeter posed a threat to the reliability of the results as it is not the perfect insulator and therefore cannot maintain all the heat energy. If the heat energy cannot be maintained, the experimental values will not be reliable because not all the energy will have been accounted for. Through our qualitative observations, the change in temperature could be felt from the outside of the cup, indicating heat escaping through the cup.

Due to this insulation problem with the styrofoam cup, a large amount of heat was lost in the reaction, which resulted in unreliable data results and inevitably, a large percentage discrepancy of An improvement to assure reliable results would be to make use of a bomb calorimeter when calculating the heat energy change in a reaction.

Unlike styrofoam cup calorimeters, bomb calorimeters are equipped with better insulation, allowing for more reliable and accurate results.

The uncertainty is extremely signicant as it highlights how the nal answer is not precise. The difference between the literature value and the highest possible experimental enthalpy change value is Calculation: 1 As mentioned above in the conclusion, to improve the reliability of the results and prevent the heat from escaping, hess law experiment lab report, a bomb calorimeter could be used. Although it may not be perfect and still have some limitations of its own, it has better insulation in relation to the styrofoam cup calorimeter and so can provide more reliable results.

Faulty Measuring Instruments Another systematic error present in the experiment was that the electronic balance was faulty in its reading, providing constantly changing values.

When recording the mass, we did not take into account this uncertainty of 0. If the instrument is faulty, inform the hess law experiment lab report and use another electronic balance.

This was however still a very minor error. Chemistry Avinash Bharwaney 12 Systematic Errors Systematic Errors Systematic Errors Error Comment Improvement Particles of reactant left in the weighing boat Another minor systematic error included hess law experiment lab report fact that there were particles of reactant left in the weighing boat after pouring the reactant into the calorimeter.

This meant that the mass in the calorimeter was not what was recorded and in fact, slightly less, affecting the reliability of the results.

In order to make sure that the majority of the particles react in the experiment, a brush or tissue can be used to scrape the remaining particles from the weighing boat into the calorimeter.

This however does create a number of problems, the rst being that the reaction would have already started and so adding additional reactant into the calorimeter during the reaction may affect the fairness of the experiment. Another problem that may arise would be that the particles may get attached to hess law experiment lab report tissue. With the exception of the electronic balance, all the measuring instruments required us to rely on our own personal judgement and perception to manually read the scale thermometer and judge where the bottom of the meniscus was measuring cylinder.

This led to uncertainty and human error as it was difcult to pinpoint the exact volume of a solution. This random error is one that will occur in any experiment, however the magnitude of the error can be subdued if the person taking the reading stays constant ie.

This is to minimize potential misreadings and reduce Parallax error. Increasing the number of trials done for each experiment also would reduce the misreadings as averaging over a large number of values hess law experiment lab report counter any misreadings made. Chemistry Avinash Bharwaney Read Free For 30 Days, hess law experiment lab report. Uploaded by api Flag for inappropriate content. Related titles. Carousel Previous Carousel Next, hess law experiment lab report.

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hess law experiment lab report

 

Hess’s Law Labs. By Austin Lee, Alayna Baron, Lily Zmachinski. This experiment taught us how to use Hess’s law to calculate the energy change in a reaction through experimentation. We learned how to use the sum of the individual reactions in our reaction to calculate it’s change in energy with experimental data. In this lab we. Nov 16,  · Liam Weinert. Hess Law Experiment. November 16, Background Information: The purpose of the performed experiment was to prove Hess Law through the use of calorimetery and to determine the standard enthalpy of formation of magnesium oxide through the use of the reactants magnesium, magnesium oxide and hydrochloric acid Calorimetery is an extremely accurate process /5(15). May 30,  · Hess's Law Lab Demonstration with NaOH and HCl (Part 2: Hess's Law and Heats of Formation - Duration: Lab Experiment # Heat of Neutralization.