Question

31. When 75.00 mL of 0.1500 M Silver nitrate and 75.0 mL of 0.150 M HCl are mixed in a constant-pressure calorimeter, the temperature of the mixture increases from 22.00 °C to 24.11 °C. The temperature increase is caused by the following reaction: AgNO3(aq) + HCl(aq) AgCl(s) + HNO3(aq) Calculate AH for this reaction in silver nitrate, assuming that the combined solution has a mass of 150.0 g and a specific heat of 4.184 J/g °C. A. -128.00K) B. 128.00 KJ C. 117.7KJ D. -117.7KJ

Answer 1

75 ml 0.1500 M Silver nitrate (AgNO3) contains 75 x 0.15 Looo mole of AgNO3 0.01125 mole of AgNO₃ 75 ml of 0.150M Hel 그 754o.15 0.01125 mole of otel = Mass of solution = 1500g specific heat(s) = 4.184 T 19°C temperature change (24.11 - 220°C 2.11°c Required heat to increase temperature of 150g of solution from 22°C to 24.11°C is Heat (8)= ms at (150 X4184 X 2.11) 1324 24 J 그 1324 KJ According the reaction → AgNO, Cag)+Hc1 (09) Ager(s) +HN03(09) from stoichiometry we learn that I mole of AgNO3 and 1 mole of Hel act as reactants. That means their molas ratio is 1:1

Now, In the given contant bressure edocumeler, 001125 mol of AgNO₃ reacts with 80 125 mol of Hel. So, we can write that when 0.01125 mol of both the reactants a react then 1. 324 kJ of heat is given off by the reaction system. Therefore, when one mole of both the reactants react then the heat released by the reaction system is 1.324 KJ 0.01125 moles 1.324 KJ X 1 1 mole → mole 0.01125 mole 117 709, 86 J 117.7 KJ tence as the solution absorbs energy as heat hence the reaction release the same amount of heat. 117.7KJ So, A Hewn The correet option is (D).(-177.7KI)