

InterviewSolution
Saved Bookmarks
1. |
A sample of `0.16 g CH_(4)` was subjected to combustion at `27^(@)C` in a bomb calorimeter. The temperature of the calorimeter system (including water) was found to rise by `0.5^(@)C`. Calculate the heat of combustion of methane at (a) constant volume and (b) constant pressure. The thermal capacity of calorimeter system is `17.0 kJ K^(-1)` and `R = 8.314 J K^(-1) mol^(-1)`. |
Answer» Heat of combustion at constant volume, `DeltaU` `=`Heat capacity of calorimeter system xx Rise in themperature `xx ("Molecular mass of compound")/("Mass of compound")` `Deltan = 1 - 3 = 2,T = 300 K, R = 8.314 xx 10^(-3) kJ K^(-1) mol^(-1)` `DeltaH^(Theta) = DeltaU^(Theta) = DeltanRT` `=- 850 + (-2) xx 8.314 xx 10^(-3) xx 300` `=- 850 - 4.988 =- 854.988 kJ mol^(-1)` |
|