Our calculations of enthalpies so far have involved covalent substances. Now we need to look at the enthalpy changes involved in the formation of giant ionic lattices. Lattice enthalpy is defined as either the: ’the enthalpy change that occurs when one mole of a solid ionic crystal is broken into its ions in the gaseous state‚ at standard temperature and pressure. Because all the bonds in the ionic lattice are broken‚ it is an endothermic process‚ ∆H is positive. ’ The IB uses this definition
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IB KYAW WAI IB1I KYAW WAI IB1I CHEMISTRY IA (2) TITRATION OF ACID & ALKALI Name: KYAW WAI Date: 5th February 2013 IA CRITERIA ASSESSED: DCP‚ MS Declaration I declare that this report I have submitted is my own original work and I have acknowledged the use of words or ideas of another person. Signature: ______________________________ Marks: ______________________________ Aim of the experiment: The aim is to determine the water of crystallization of a diprotic acid by
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CALORIMETRY INTRODUCTION Calorimetry is used to determine the heat released or absorbed in a chemical reaction (1).Trustees of darmouth college states that (1) is used to determine the heat released or absorbed in a chemical reaction. To determine the heat released or absorbed in a chemical reaction an instrument called calorimeter is used. A calorimeter is an instrument used for measuring the heat of a reaction during a well defined process (2). Brucat states that (2) a calorimeter is an instrument
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Chem 17 ▪ General Chemistry Laboratory II Experiment 1 Calorimetry INTRODUCTION Chemical reactions are usually accompanied by the evolution (exothermic reaction) or absorption (endothermic reaction) of heat energy. When measured at constant pressure‚ the heat evolved (qp < 0) or absorbed (qp > 0) is equal to the enthalpy change‚ symbolized by ΔH. ΔH is positive for an endothermic process and negative for an exothermic one. If H f is the enthalpy of the final state and Hi of the initial state
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Experiment 1: Calorimetry INTRODUCTION In the calibration of the calorimeter‚ the net ionic equation used is H+(aq) + OH-(aq) H2O(l). The reaction released heat and is said to be exothermic. HCl is the limiting reactant of the reaction and o.oo5 moles of it was used. The heat generated by the reaction is 55.8 kJ. The sign of T of the reaction used for calibration is opposite to that of H. In the determination of heats of reaction‚ the reaction of 15 mL 1 M CuSO4 + 0.05 g Zn produced a
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Determining an Enthalapy Change of Reaction Purpose of Experiment The purpose of this experiment is to determine the enthalapy change for the displacement reaction: Zn(s) + CuSO4(aq) Cu(s) + ZnSO4(aq) Hypothesis With this experiment I can also not make a hypothesis‚ because we did actually not do the experiment‚ but we were told that the temperature would make a sudden drop ‚ but we can measure the ΔT of the surrounding. The reaction is endothermic because the system will take in energy
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CHEMISTRY DETERMINATION OF ENTHALPY CHANGE OF NEUTRALIZATION IA Criteria Assessed: DCP CE MS Introduction When an alkali neutralizes an acid‚ a salt and water are formed. Aqueous hydrogen ions (H+(aq)) from the acid react with the hydroxide ions (OH- (aq)) from alkali‚ forming water. The identity of salt will depend on the nature of the acid and alkali used. H+(aq) + OH- (aq) → H2O(L) The combination of H+ and OH- ions in this way releases energy. In this practical‚ the
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Enhtalpy change - Hess’ law Experiment #7 Date performed: March 4‚ 2014 Presented by: Sam Tabah(I.D.#1402433) & Giuliano Amato(I.D.#1328425) General Chemistry 202 Nya-05 (00006) Vanier college Part A. Objective: The objective of this lab was to determine the standard heat formation (∆H°F) of MgO‚ using a calorimeter and determining the enthalpy of two reactions. Applying Hess’ law we were able to determine the standard heat formation of MgO. Introduction
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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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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 a substance
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