Question

When there is a mixture of different chemical components, for example, H2O(0.8 mass fraction), CH3COONa (0.17 m.f) and NaHCO3(0.03 m.f) at 25℃.

How much of enthalpy do I need to get rid of H2O liquid by vaporizing it??

or just mentioning the idea to solve this problem would be helpful. Thank you.

(*The Original boling point of CH3COOH is 118.1℃, can I preserve the same amount of CH3COOH after removing all the H2O??

Answer 1

Given, mass fraction of H₂O = 0.8

mass fraction of CH₃COONa = 0.17

mass fraction of NaHCO₃ = 0.03

we can assume the total weight of mixture to be 100gm

then mass of H₂O will be 0.8 * 100 = 80gm

and mass of CH₃COONa will be 0.17 * 100 = 17gm

and mass of NaHCO₃ will be 0.03 * 100 = 3gm

mole fraction of H₂O = weight of H₂O / molar mass of H₂O = 80 / 18 = 4.44moles

we know, the enthalpy of vaporization of water at 25°C = 43.988 kJ / mol

For 4.44 moles of H₂O, the enthalpy of vaporization required = 43.988 * 4.44 = 195.306 kJ