Using the given boiling points, predict which compound has the higher vapor pressure at a given temperature.
A. ethanol (C2H6O, bp 78 degrees C) or
1-propanol (C3H8O, bp 97 degrees C)
B. hexane (C6H14, bp 69 degrees C) or
octane (C8H18, bp 125 degrees C)
A.) ethanol
B.) hexane
To predict which compound has the higher vapor pressure at a given temperature, you need to consider their boiling points. The compound with the lower boiling point will generally have the higher vapor pressure at a given temperature.
A. In this case, ethanol has a boiling point of 78 degrees Celsius, while 1-propanol has a boiling point of 97 degrees Celsius. Since ethanol has the lower boiling point, it is expected to have the higher vapor pressure at a given temperature. So, ethanol will have the higher vapor pressure.
B. For hexane and octane, hexane has a boiling point of 69 degrees Celsius, while octane has a boiling point of 125 degrees Celsius. Again, the compound with the lower boiling point, which is hexane in this case, will have the higher vapor pressure at a given temperature. Therefore, hexane will have the higher vapor pressure.
In summary, the compounds with the lower boiling points, ethanol and hexane, will have the higher vapor pressures at a given temperature.