Estimation of Vaporization Enthalpy of Ethanol using Clausius-Clapeyron Equation - Prof. S, Quizzes of Chemistry

Download Estimation of Vaporization Enthalpy of Ethanol using Clausius-Clapeyron Equation - Prof. S and more Quizzes Chemistry in PDF only on Docsity! CHEM443 Physical Chemistry I Name ________________________ Fall 2010, Section 010 Quiz 8 1.(10 Points) A). Using the following data, estimate the vaporization enthalpy of ethanol. State any approximations you use. B). Compare your result to the heat of vaporization at the normal boiling point of ethanol. Data in Table 6.1 of your Handbook may be helpful. P (mm Hg) 40 100 400 760 1520 3800 7600 15200 30400 45600 T °C 19.0 34.9 63.5 78.4 97.5 126.0 151.8 183.0 218.0 242.0 Table data obtained from CRC Handbook of Chemistry and Physics 44th ed. Solution: Using the Clausius-Clapeyron equation with the assumption that the vapor is ideal gas and the vaporization enthalpy is constant over the temperature range given in the data set: € d (ln P) = ΔHv R d T T2 ln P + C1 = - ΔHv RT + C2 ln P = - ΔHv R       1 T + b Thus, plot ln (P) versus (1/T). The slope multiplied by –R is the vaporization enthalpy (red diamonds are the fit to the experimental data shown as black circles)