Question

If 1.0 kcal of heat is added to 1.2 L of `O_(2)` in a cyclinder of constant pressure of 1 atm , the volume increase to 1.5 L . Calculate `DeltaU` and `DeltaH`of the process.

Answer 1

Correct Answer - `DeltaE= 0.993 Kcal , DeltaH= 1 kcal`
`W =- P_("ext")(V_(2)- V_(1)) = - 1 (1.5 - 1.2) = - 0.3 L atm = - 7.235 "cal"`
`DeltaU = q+ w`
`= 1-0.007235= 0.993 cal`
`q = DeltaH = 1 kcal`