Answer :
Final answer:
To find the vapor pressure of isooctane at 38 degrees Celsius, the Clausius-Clapeyron equation is used, incorporating the given enthalpy of vaporization and the temperature conversion to Kelvin.
Explanation:
To determine the vapor pressure of isooctane at 38 degrees Celsius, we can use the Clausius-Clapeyron equation, which relates the enthalpy of vaporization to the pressure and temperature:
ln(P2/P1) = ΔHvap/R (1/T1 - 1/T2)
Where P1 and P2 are the vapor pressures at temperatures T1 and T2 respectively, ΔHvap is the enthalpy of vaporization, and R is the ideal gas constant (8.314 J/(mol·K)).
In this problem, we consider the normal boiling point temperature (T1) to be 98.2 degrees Celsius, which we convert to Kelvin (T1 = 371.35 K), and the corresponding pressure (P1) is atmospheric pressure, or 101.3 kPa. We want to calculate the pressure at 38 degrees Celsius (T2 = 311.15 K). The enthalpy of vaporization (ΔHvap) is given as 35.8 kJ/mol, which is 35,800 J/mol.
Rearranging the equation for P2 and substituting the known values, we can calculate the vapor pressure of isooctane at 38 degrees Celsius.
