Question

Mail - yitsi almeida - Outlook Q Study 16 Terms Chem 6 Flash * Q Potential and Kinetic Energy Rex m/courses/1093038/quizzes/1706760/take Question 4 x Get Homewe 2 pts Determine the heat required to raise the temperature of a piece of iron(mass = 245 g) that starts at 25.0°C and is heated to 85.0°C. The specificheat capacity of iron is 0.449 J/gºC. SHOW WORK Upload choose a File D Question 5 4 pts A4.98 g sample of phenol (C,H,OH, molar mass - 94.11 g/mol) was combusted in a bomb calorimeter with a heat capacity of 4,80 kJ/°C. If the temperature rose from 26.8°C to 58.9°C. determine the value of AH"comb for phenol. SHOW WORK and REPORT YOUR ANSWER InkJ/mol. Upload Choose a File 2015. 2015. ppt

Answer 1

Heat required, Q = mass of ison x heat capacity of ison x ot = 245 g x 0.449 I. *(85.0–23.0) Q =16600 J Heat change, Q = Heat capacity of calorimeter XAT = 4.80 kJ < (58.9–26.8) °c = 154.08 kJ Molar mass of phend = quill glmol OD So, molar heat at constant volume = DE - 4.98 g phenol 94.11 g phenol → 154.08 kJ of heat 154.08 x 94.11 kJ = 4.98 dies AE = - 2911.7 kJ/mol combustion equation : CGHS OH (s) + 70₂ (9) 6CO₂(g) + 3 H₂O(1) phenol

- Aug = products - gaseous moles of gaseous moles of reactants So, Ang = 6-7 = -1 Now, AH = SE + Ang RT = -2911.7 kJ + (-1* 8:314 I _ * 298k) Kimol 1000 J/kg → AH = -2914 kJ/mol o swixen = E AFH of products - E AFHO of reactants = [6(-3935) +66-24118)] kJ - (-127.33 + o] het on mo > Shaxn = |- 3684 kJ/mol since Ario; it's EXOTHERMIC. 7 DE = qtw = 114.0 kJ +(-294.6) kJ → DE = 1 - 180.6 BJ