* Chemical Safety: ticker out for any spills. maintain the country clean * Heat Safety: stay at a safe distance from the fire
* Sharp Object Safety: take cautiousness when working with Mg wire * Safety spectacless: in instance of splashes from the chemicals * Horseplay will non be tolerated
Purpose: The intent of this lab is to happen the heat content of burning of Magnesium. In other words the intent of this experiment is to find the heat content of formation of Mg oxide. Background Information:
Ices are a type of handheld pyrotechnic that burns for about a minute while giving off small flickers. They are composed of two fuels. an oxidant. and pyrotechnic colourss ( to add ocular involvement ) . There’s besides a compound that holds them together. either dextrin or cellulose nitrate. However. the most of import constituent to a ice is the Mg. The map of the Mg in ices is to supply the bright visible radiation to the ice. When Mg is burned it gives off this bright white visible radiation. which makes the ice freshness. Certain ordinances to ices and bangers exist because of how unsafe they can be. Harmonizing to the American Pyrotechnic Association. in the province of Georgia. a individual must be 18 or older to buy any pyrotechnic.
Besides. Georgia does non let any pyrotechnic that explodes or shoot into the air. nevertheless ices. Poppers. or any noisemaker is allowed. Numerous histories of accidents from ices occur every twelvemonth because ices burn at really high temperatures and really rapidly. During the month of July there was a higher accident rate. There were 1. 100 instances of kids acquiring burned from ices. and 1. 100 instances of pyrotechnics besides. MgO ( s ) + 2HCl ( aq ) = MgCl2 ( aq ) + H2O ( cubic decimeter ) and besides Mg ( s ) + 2HCl ( aq ) = MgCl2 ( aq ) + H2 ( g ) . This reaction would be exothermal because it is let go ofing heat and the concluding temperature is higher than the initial temperature. The recognized value for the heat content of burning of Mg is -602 KJ/mol.
Heat of Combustion of Mg Data Table
Heat of Combustion of Mg Data Table
Balanced Equation| Reaction| Type of Reaction| Data|
H2 ( g ) + 1/2O2 ( g ) =H2O ( cubic decimeter ) | Formation of liquid H2O from its elements| Synthesis| Hf=-286KJ/mol| MgO ( s ) + 2HCl ( aq ) = MgCl2 ( aq ) + H2O ( cubic decimeter ) | Solid Mg oxide reacts with aqueous hydrochloric acid| Double Replacement| Hr= -133 KJ/molInitial: 20. 0 CFinal: 27. 9 C| Mg ( s ) + 2HCl ( aq ) = MgCl2 ( aq ) + H2 ( g ) | Magnesium metal is added to aqueous hydrochloric acid| Single Replacement| Hr=-168 KJ/molInitial: 19. 8Final: 27. 7Mass: . 388g| Data Analysis:
A. Determine the heat produced or absorbed when MgO ( s ) is reacted with HCl ( aq ) . This is Reaction 2.
B. Determine the heat produced or absorbed when Mg ( s ) is reacted with HCl ( s ) . This is reaction 3.
C. Using Hess’s Law of Heat Summation and the balanced equations for the three reactions. cipher the heat content of reaction for the burning of Mg.
D. Compare the experimental value for the heat content of burning of Mg t the recognized value that was found during preliminary probe. Calculate the per centum mistake of the experimental information.
E. A ice contains 0. 11g of Mg. If all of the Mg in a ice reacts. how much heat is the ice capable of bring forthing as it burns? Use the experimental.
Paragraph # 1: The intent of this probe was to happen the heat content of burning for Magnesium. A series of chemical equations were used to happen the heat content of burning for Magnesium. Procedures performed during the class of this experiment were divided under three classs: Chemical reaction of HCl with MgO. HCl with Mg. and Oxygen with Hydrogen. In the reaction of O with H. happen the heat of formation of one mole of liquid H2O from the component composing a balanced equation. In the reaction of HCl with MgO. step 100. 0 milliliter of hydrochloric acid and add it to a calorimeter. which is an instrument used to assist happen the heat of a reaction. and so add 1. 00 g of Mg oxide. Stir and record any temperatures. ( initial and concluding ) . In the reaction of Mg with HCl. pour 100. 0 milliliter of hydrochloric acid into the calorimeter. and so put the Mg thread into the calorimeter and splash. Stir the substance in the calorimeter until the highest temperature is recorded. A calorimeter. as stated earlier. measures heat capacity. In this lab the calorimeter was Styrofoam cups placed on top of one another at the rims.
Paragraph # 2: Scientists collect two types of informations: qualitative and quantitative informations. Qualitative information is field of probe that answers the why and how of the experiment. Qualitative information is collected based off of scientist’s senses. Contrariwise quantitative information is numeral informations intending it can be measured. Some illustrations of qualitative informations in the gesture of atoms and molecules lab include the white colour and the soft texture of the MgO. This besides includes the Ag colour of the Mg thread and the transparence of the HCl. The quantitative information in this experiment was measured utilizing a thermometer and a balance. The quantitative include addition of the initial temperature of HCl from 20. 0 grades Celsius to 27. 9 grades Celsius after Mg oxide was added to the HCl. It besides includes the19. 8 grades Celsius of the initial temperature of the HCl and so 27. 8 grades Celsius after the Mg strip was added to the solution. Additional quantitative informations includes the heat of formation of H2O at -286KJ. the heat of reaction of MgO with HCl at -133KJ. and the heat of reaction of Mg with HCl at -168KJ.
Paragraph # 3: In this experiment the heat of burning could non be collected due to the fact that the resources needed to mensurate the heat content of burning were non provided. In order to get the better of this obstruction. pupils used the heat of reaction of three chemical equations. Using the heat of reaction the pupils used Hess’s Law of Heat Summation to happen the heat of burning. To happen the heat content of the reaction. we add the heat content alterations for a series of reactions. The reaction q=mc ( delta ) T is used to cipher the sum of heat gained or lost during a reaction. Q stands for the heat created or lost. m stands for the mass of the reactant. degree Celsius is the specific heat of the reactant and T is the alteration in temperature. During this experiment. a calorimeter was used. Ideally. the calorimeter would non let any heat to come in or get away. This allows for accurate temperature readings.
During this experiment our group faced big a per centum mistake. Our per centum mistake was 48. 8 % . After discoursing what the possible ground for such a big per centum mistake with group couples and an teacher we have concluded that the balance was the cause of such a big per centum mistake. The mass of our Mg wire was. 39 gms where other groups had about. 1 gms of Mg wire. The calorimeter does non let heat to flight ; nevertheless a calorimeter made of Styrofoam was used. which could lend to the per centum mistake because there possibly little holes in the cups or the top cup may hold could hold come off during the reaction. The usage of a one-piece calorimeter could perchance cut down the per centum mistake. In massing the substances pupils could compare their multitudes with other groups before continuing with the experiment to guarantee that no groups are rolling from the norm. Stiring the solutions longer could besides help in cut downing the per centum mistake.