Suppose the vapor pressure of a substance is measured at two different temperatures. (a) By using the Clausius–Clapeyron equation (Equation 11.1) derive the following relationship between the vapor pressures, P1 and P2, and the absolute temperatures at which they were measured, T1 and T2: (b) Gasoline is a mixture of hydrocarbons, a component of which is octane (CH₃CH₂CH₂CH₂CH₂CH₂CH₂CH₃). Octane has a vapor pressure of 13.95 torr at 25 °C and a vapor pressure of 144.78 torr at 75 °C. Use these data and the equation in part (a) to calculate the heat of vaporization of octane. (c) By using the equation in part (a) and the data given in part (b), calculate the normal boiling point of octane. Compare your answer to the one you obtained from Exercise 11.81. (d) Calculate the vapor pressure of octane at - 30 °C.

Video transcript

Everyone's aware the vapor pressure of plantain measured at two different temperatures and the vapor pressure of plantain at 15°C. 55. Tour. Never pressure at 40°C is age of 56. Tour last Catholic the entropy of vaporization of plantain. Using the classes clapper an equation recall that this equation is L. N. The second paper pressure divided by the first paper pressure equal to negative entropy of vaporization divided by art which is the gas constant. This one for the second temperature -1 over the first temperature for the first favorite pressure. 1355. Tour for the second paper pressure You have Andrew 56. Tour For the first temperature 15°C. We need to convert it to Kelvin. So we need to add 273.15 Kelvin. Here we get 288 15 Kelvin. For the second temperature We have 40°C. We need to add 273. And we get 313.157. So now we can plug in the values and solve for the entropy of the vaporization. L. N. Angel 56. Tour By about 355. Tour equal to negative interfere vaporization By by the gas constant which is 8.314 caramel Calvin Times one by by 313.15 Kelvin minus one. About 288 15 kelvin Gonna get 0.88 equals the negative entity of vaporization. Got about 8.314. Just come on name's kelvin. 0.000 27705. They get negative 3176 equal to negative entropy of vaporization By about 8.314. Those caramel name's Calvin. Not the most kind of 3076. those primal. How's kelvin? Is that equal to negative entropy of vaporization for the entropy of vaporization? We get 26405 those promote. And now if we convert this to kill jews promote goals from all. And in one killer draw We have 1000 goals You get 26.4. So just promote. Thanks for watching my video and I hope it's up for