Question

The heat of vaporization ΔHv of dichloromethane CH2Cl2 is 28.0 /kJmol . Calculate the change in entropy ΔS when 3.3g of dichloromethane boils at 39.8°C . Be sure your answer contains a unit symbol and the correct number of significant digits.

Answer 1

Answer:

$\Delta _VS=3.48x10^{-3}kJ=3.48J$

Explanation:

Hello,

In this case, the change in the entropy, by knowing the change in the enthalpy and the temperature for a vaporization process is given by:

$\Delta _VS=\frac{\Delta _VH}{T_V}$

Thus, we start by computing the change in the enthalpy for the 3.3g of dichloromethane  as shown below:

$\Delta _VH=3.3gCH_2Cl_2 *\frac{1molCH_2Cl_2}{84.9gCH_2Cl_2}*28\frac{kJ}{molCH_2Cl_2} =1.09kJ$

Finally, the change in the entropy, considering the temperature in kelvins:

$\Delta _VS=\frac{1.09kJ}{(39.8+273.15)K}\\\\\Delta _VS=3.48x10^{-3}kJ=3.48J$

Best regards.