Question

. (15. A 1.600g sample of quinone (C6H,02) was burned in a bomb calorimeter whose total heat capacity is 7.854 kJ/°C. The temperature of the calorimeter increases from 21.34 °C to 32.57 °C. What is the heat of combustion per gram of quinone? Per mole of quinone? (10 pts.)

Answer 1

Answer: The molar heat of combustion for quinone is 5959 KJ/mole and -51.12 kJ/gram Here, two Heat Transfers are involved. Heat of Comb. of quinone & Heat gained by Calorimet .: 0+02 = 0 NACH + Ccal AT = 0 In this problem, n = 1.69m quinone o na 1:6. Ju duinone x_1 mote quinone 108.09 gm quinone Here, n = 0.01480 mole quinone Cal = 7.854 kJ/C " = 7954 JAC AT = Tina - = 32.57-21:34 Tinitial - =111-23°c Here, q = n AH = 0.01480 x 4H: 2 = Cal AT = 7854 5/8 x 71-23° ¢ 88200.42 J 88.2 kJ Now We know that a, tq₂ = 0 is 0.01480 ACH +88-2 = 0. Act = -88.2 - 1959.46 kJ/mole Ach - 0.01480 u for I gram - The arram = -88.2 KJ F 55.12 KJ/ gram 1.6 gram