Question #a165f

1 Answer
Dec 8, 2017

The enthalpy is -"3.6 kJ/mol".

Explanation:

The answer can be found out using the Clausius Clapeyron equation:

ln(P_2/P_1) = -(DeltaH_(vap)) / R (1/T_2 - 1/T_1)

Here, P_2 = "290 torr" and P_1 = "242 torr".

Don't forget to change temperature to absolute Kelvin (Celsius + 273 approximately).

So, T_2 = "323 K" and T_1 = "373 K"

R = "8.314 J/mol"cdot"K"

ln("290 torr"/"242 torr") = -(DeltaH_(vap)) / ("8.314 J/mol"cdot"K") (1/"323 K" - 1/"373 K")

= -"3624.9 J/mol" = -"3.6 kJ/mol"

Since the enthapy is negative , the liquid could be condensing!