The final temperature of the calorimeter is 85.71 degree C.
Heat of the reaction is -1235 kJ/mol
Heat discharged at the time of reaction is 1235 kJ/mol
The moles of ethanol are calculated by using the formula mass of ethanol / molar mass of ethanol
= 12.8 g / 46 g/mol = 0.278 moles
Thus, the no. of moles of ethanol is 0.278 moles
The heat released when ethanol is combusted is:
0.278 moles × 1235 kJ/mol = 343 kJ
The final temperature is determined as,
343 kJ = (heat capacity) (temperature difference)
343 kJ = 5.65 (T – 25)
T-25 = 343 / 5.65
T-25 = 60.71
T = 85.71 degree C
Thus, the final temperature is 85.71 degree C.