Chemical Thermodynamics Question 424
Question: For complete combustion of ethanol, $ C_2H_5OH( l )+3O_2( g )\xrightarrow{{}}2CO_2( g )+3H_2O( l ), $ the amount of heat produced as measured in bomb calorimeter, is $ 1364.47kJmo{{l}^{-1}} $ at $ 25{}^\circ C $ . Assuming ideality the enthalpy of combustion, $ {\Delta_{c}}H $ , for the reaction will be: $ ( R=8.314kJ,mo{{l}^{-1}} ) $
Options:
A) $ -1366.95kJmo{{l}^{-1}} $
B) $ -1361.95kJ,mo{{l}^{-1}} $
C) $ -1460.95kJ,mo{{l}^{-1}} $
D) $ -1350.50kJ,mo{{l}^{-1}} $
Show Answer
Answer:
Correct Answer: A
Solution:
- $ C_2H_5OH( l )+3O_2( g )\xrightarrow{{}} $
$ 2CO_2( g )+3H_2O( l ) $ Bomb calorimeter gives $ \Delta U $ of the reaction Given, $ \Delta U=-1364.47kJmo{{l}^{-1}} $
$ \Delta n_{g}=-1 $
$ \Delta H=\Delta U+\Delta n_{g}RT $
$ =-,1364.47-\frac{1\times 8.314\times 298}{1000} $
$ =-1366.93kJmo{{l}^{-1}} $
