Question

The heat of vaporization of acetic acid is . Calculate the change in entropy when of acetic acid condenses at .

Answer 1

The question is incomplete, the complete question is;

The heat of vaporization ΔHv of acetic acid HCH3CO2 is 41.0 /kJmol. Calculate the change in entropy ΔS when 954.g of acetic acid condenses at 118.1°C. Be sure your answer contains a unit symbol. Round your answer to 3 significant digits.

Answer:

-1.67 JK-1

Explanation:

Since Heat of vaporization of acetic acid = 41.0 kJ/mol

Therefore:

Heat of condensation of acetic acid = -41.0 kJ/mol

Mass of acetic acid = 954 g

Temperature of condensation = 118.1 °C or 391.1 K

Number of moles of acetic acid = 954 g/60g/mol = 15.9 moles

Heat evolved during condensation = 15.9 moles *  -41.0 kJ/mol = -651.9 KJ

Entropy change (ΔS) = Heat evolved/ Temperature = -651.9 KJ/391.1 K

Entropy change (ΔS) = -1.67 JK-1