Question

Experiment #9: Heats of Reaction Pre-Lab Questions Name Date Lab Mamal helps in answering the following questions 1. A reaction in which heat is absorbed is called a. Endothermic b. Exothermic c. Cooling d. Heating 2. A reaction where heat is released is called a. Endothermic b. Exothermic c. Cooling d. Heating 3. The energy change of a reaction that occurs at constant pressure is called the a. Total energy change b. Work c. Heat of reaction d pressure 4. Endothermic reactions have a positive AH a. True b. False 5. Exothermic reactions have a positive AH a. True b. False 6. Sweat evaporating from skin would be described as endothermic. a. True b. False 7. Wood burning in a fire as exothermic. a True b. False 8. A neutralization reaction was carried out by mixing 100 ml of IM NaOH to 100 mL of HCI solution in a calorimeter. Before mixing, the temperature of the solution and the calorimeter was 25°C. After mixing the solutions, the temperature of the solution and the calorimeter was raised to 45°C. Heat capacity of the calorimeter and water were 25 JC and 4.184 J/g °C (specific), respectively. Calculate Enthalpy (AH) of the neutralization reaction. Consider the density of the solution is 1g/mL. AH heat capacity X AT for calorimeter specific heat capacity X mass of water X AT for water

Answer 1

ti @ Endotherinės 2. Exothermie 3. ③ Heat of reaction 4. @ Torue (For endothermic reaction 4H20) 5. Falbe For escothermie reaction AH2O) 6. @ True 7. @ True O TAG Jorba = urou 8. Total volume of the solution = (100+100) - 200 ml 99 Mass of 99 99 = (200x1) = 2009 [density = 1 glme] Heat released by the neutralisation reaction (ah) = Heat capacity of Calorimeter x change in temperature + Mass of solution X specific heat capacity of solution cwater) x change in telukerature' = 125X (45-25) + 2004 4.184x(45-25) J - 25X20 + 200 +4:184 x20) 17236 J = 17.236 KJ .: Heat of neutralisation - - 17.236 kJ