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2025-2026 (CHEM 103) LAB REPORT 4 | PORTAGE LEARNING| GRADED A+
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Chemistry Lab Report May 10, 2025 Experiment # 4 Title: Thermochemistry Purpose: Through the acid-base experiment, we can determine the heat of the reaction, or ΔH. We can also measure how much heat it takes to raise 500 grams of water by 15 degrees Celsius through the heat of combustion of a hydrocarbon fuel. Procedure: Acid Base Experiment: NaOH + HCl → NaCl + H₂O ⃤ H=? Salt water is being formed Determine the weight (Calorimeterer)
NaOH + HCl yields NaCl + H2O, Mix in calorimeterer and check temperature. Calorimeter is cleaned out and dried.
calorimeter. Part 2: Acid Base Reaction ● Initial temperature of HCl + calorimeter: 22.8 C ● Highest temperature : 28.6° C and then slowly receded and stayed at 28.4 ° C ● △ T =5.8° C(or K) is the overall change in difference ● Heat gained by solution : 5.8 K x 100 g x 4.18 J/K-G = 2424.4 J (amount gained by solution)
Part 3 Heat Combustion Fuel Initial 203.2383 grams Final mass 200.2244 grams How much was used? 3.0138 grams Water Initial: 21.4 ° C Final Temperature: 37.2° C △ T =15.8 ° C temp change Copper pan is 218.87 grams 500 mL x 1g/1mL (density of water is one gram /per mililiter) 500mL x 1g/1mL @ 24C= 500g which is the mass of the water that we are using. Because density of water is 1 - 1 it makes it easy to know the conversions and this will be used in the change of heat formula. The heat is transferred from the fuel into water and copper pan; measuring the differenc ein the mass of the fuel but the heat that we measure we will assume that it is all being transferred int o the water in the copper pan. Change in heat △q=M(mass) C (Heat capacity) △T (change in temp) △ q=(500 g x 1.00 cal/g - C) + (copper pan 218.87 grams x acc. Val 0.092 Cal/g C) x 15.8°C (change in temp)
Example reaction (exothermic): Methane reacts with oxygen combustion reactions to produce CO₂ and water. CH₄(g) + 2O₂(g) → CO₂ (g) + 2H₂O (i) ⃤ H = - 212.8Kcal Exothermic Reaction (heat given off for every mole, negative sign shows heat given off) In thermochemical reactions, the heat change is added onto the reaction that is represented by Delta H (enthalPY) and it is added to the end of the reaction and gives us a heat value. For every 1 mole of Ch4 that burns we get a (The change in enthalPY) - 212.8 Kcal (Extensive) Is we double this and go 2mol CH4= we would double - 425.6 Kcal Extensive Property of chemical reactions meaning it depends on the amount ● Not all properties are extensive, some are intensive ● An example of this is density-density of water is the same if you have a few drops or a lot of it, the density is the same (intensive property) Reactions give off heat in one direction and can pick up heat in another direction Example Reaction (Endothermic): Calcium carbonate is heated and broken downas calcium oxide as well as CO₂ given off CaCO₃ → CaO + CO₂ ⃤H=+42. Kcal Delta H is +42.4 Kilo Calories