Question

In the lab, a student burns a 0.509g sample of 9,10- anthracenedione(C14H8O2) in a bomb calorimeter containing 105.0g of water. The temperature increases from 25.20 degrees celcius to 28.20 degrees celsius. The heat capacity of water is 4.184J79)(c). The molar heat of combustion is --6464 Kj per mole of 9,10 anthracenedione. Calculate the heat capacity of the calorimeter. MacBook Air

Answer 1

Solution given, mass of 9,10- anthracenedione (CuHg(z) = 0.509g mass of water = 105 g Initial temperature (ti) = 25-20°C Final temperature (t) = 28.70°C Change in temperature (st) = (tf-ti). = (28.70°C-25-200) = 3°C Heat capacity of water (sw) = 4.184 J/9% Molar heat of combustion of Cu HQ O2 = -6464 kJ/mol Malarmass of Gu Ho O2 = 14X12 + 8X1 + 2x16 - २०89/nual moles of Gu H₂O = mass of Cu Hp Oz Molarmass of GuHgOz 0.509g 208g/mal = 0.0024 mal Heat of combustion of Gu Hp0, - Malarheat of combustion Xmoles of Cichel = -6464 kJ/mol X 0.0024mal > -15.5136 kJ (QcluHgO) = -15 513.65 Scani de contrained in die water = mw sw st

Heat gained by water Qu)= 1059 x 4-1845/8°C X 3°C = 1317-96 J I As we know, Heat of calorimeter Qcal) = -Qutele + Qw) =-6-15513.6 J+ 1317-965) = - (-14195.64 J) Qcal = 14195-64 J Heat capacity of calorimeter = 14195-645 3°C =4731-885/°C Ans:- Heat capacity of calorimeter is 4731-88 J/°C. Scanned with CamScanner