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

`\Delta _VS=3.48x10^(-3)kJ=3.48J`

Step-by-step 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=(\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 *(1molCH_2Cl_2)/(84.9gCH_2Cl_2)*28(kJ)/(molCH_2Cl_2) =1.09kJ`

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

`\Delta _VS=(1.09kJ)/((39.8+273.15)K)\\\\\Delta _VS=3.48x10^(-3)kJ=3.48J`

Best regards.