Introduction Enthalpy change‚ ΔH‚ is defined as the heat output of a system as it goes through a reaction under constant pressure. It is an important aspect of thermochemistry‚ which is the study of energy changes during a chemical or physical reaction . When we calculate enthalpy change‚ we always assume that the pressure is constant. We are able to calculate enthalpy change numerous ways‚ notably by the increase in heat‚ Q‚ given by an exothermic reaction or the heat absorbed by an endothermic
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the Enthalpy of a Chemical Reaction All chemical reactions involve an exchange of heat energy; therefore‚ it is tempting to plan to follow a reaction by measuring the enthalpy change (∆H). However‚ it is often not possible to directly measure the heat energy change of the reactants and products (the system). We can measure the heat change that occurs in the surroundings by monitoring temperature changes. If we conduct a reaction between two substances in aqueous solution‚ then the enthalpy of
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Experiment ENTHALPY AND ENTROPY OF ZINC WITH COPPER SULFATE The CCLI Initiative Computers in Chemistry Laboratory Instruction LEARNING OBJECTIVES The learning objectives of this experiment are to. . . ! ! determine changes in enthalpy and entropy of the reaction of zinc with copper sulfate using two methods: electrochemistry and calorimetry. compare the enthalpy values obtained by the two methods. BACKGROUND Thermodynamics is concerned with energy changes that occur in chemical and physical process
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Task 1: Assessment criterion 2.1 Determine the enthalpy change for the reaction (ΔHfθ) between zinc and copper sulphate solution‚ giving full practical details. Aim To determine the enthalpy change for the reaction between zinc and copper sulphate. Zn (s) + CuSO4 (aq) ZnSO4 (aq) + Cu (s) Introduction In the study of energy (thermodynamics) the system refers to the reacting chemicals (zinc and copper sulphate solution) and the surroundings is everything else (atmosphere
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This lab is performed in order to determine the total energy in a reaction between zinc and hydrochloric acid. The reaction is done twice‚ once to measure the heat of the reaction and again to determine the work done in the system. This is because Enthalpy equals heat plus work (∆H= ∆E+W). Heat and work can be broken down further into separate components so the equation used in lab is ∆H=mc∆T + PV. Many calculations are used in the lab to find out what cannot be measured directly (ex: volume). After
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Determining the enthalpy of neutralization by calorimetry Anam Iqbal Partner’s name: Danielle Hodgson TA’s name: Karinna Section # 003 Due date: November 24‚ 2009 Introduction The purpose of the experiment is to determine the enthalpy of neutralization reactions by calorimetry. Calorimetry‚ is the science of measuring the amount of heat. All calorimetric techniques are therefore based on the measurement of heat that may be generated (exothermic process) or consumed (endothermic process). The
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the surrounding. Hence‚ it has a positive value for enthalpy change of reaction. In contrary‚ exothermic reaction is a chemical reaction that releases heat energy to the surroundings‚ resulting in a negative value for enthalpy change of reaction. Enthalpy change of a reaction is the heat energy change in a chemical reaction‚ for the number of moles of reactants shown in the chemical equation. Standard enthalpy of reaction‚ ΔrH⊖ is the enthalpy change that occurs in a system when one mole of matter
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Measuring the Enthalpy change of combustion Abstract This simple experiment is carried out to show the difference in the enthalpy change of combustion between two fuels‚ hexane and methanol. These fuels are individually weighed before and after used as heat source to heat water in a calorimeter. The result is used to find out amount of heat transferred by the fuel‚ amount of fuel used and the enthalpy change of combustion. Introduction Enthalpy change of combustion is the enthalpy change when
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Determining the enthalpy change for the thermal decomposition of potassium hydrogen carbonate into potassium carbonate. Controlled Variables: 1. Volume of HCl ± 0.5 cm3 (± 2%) 2. Concentration of HCl‚ 3. Same mass of K2CO3 and KHCO3 within specified ranges of 2.5 – 3.0g and 3.25 – 3.75g respectively 4. Same calorimeter used i.e. polystyrene cup is used in this experiment 5. Same thermometer will be used ± 0.10K 6. Same source of K2CO3‚ KHCO3 and HCl Raw Data Results: The raw
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Capacity for a Calorimeter and of the Enthalpy of an Acid-Base Reaction Abstract The purpose of this lab was to first‚ determine the specific heat capacity of a homemade calorimeter‚ and second‚ to calculate the enthalpy of reaction for an acid-base reaction between 6M KOH and 6M HNO3. To determine the specific heat capacity of the calorimeter‚ two differing temperatures of water were measured and volume was measured and mixed within the calorimeter. The enthalpy of reaction for an acid-base reaction
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