The enthalpy of methanol, CH3OH (MW=32.0 g/mol) is -7.26 x 102 kJ/mol. Calculate the grams of methanol burned in a bomb calorimeter (Kc=727.1 J/oC) containing 1.20 kg of water (Cp=4.184 J/goC) if the temperature of the calorimeter increases by 11.38oC.

Question

aaronq · Answer

find the heat, q, that was released by the combustion reaction:

$q=mass_{water}*C_p*\Delta T$

aaronq · Answer

Next, multiply the heat, q, by the enthalpy of methanol

$H_{MeOH}*q=moles~of ~MeOH$

aaronq · Answer

When you have the moles, convert them to mass

$moles=\dfrac{mass}{Molar~mass}$

anonymous · Answer

q=5.714*10^4 J

aaronq · Answer

wait, small correction to account for the heat absorbed by the calorimeter:

$q=mass_{water}*C_p*\Delta T+Kc*\Delta T$