Question

vapor pressure, torr -dimethyl sulfoxide - benzaldehyde - cyclohexanone 150 160 170 180 temperature, °C Use the graph to answer the following questions: most volatile: dimethyl sulfoxide Which liquid is the most volatile? Which is the least volatile? least volatile: cyclohexanone dimethyl sulfoxide: °C What is the normal boiling point of each liquid? Note: your answer must be within 1°C of the exact answer to be graded correct. benzaldehyde: cyclohexanone: 1°C Suppose a beaker of benzaldehyde is put inside a sealed tank containing benzaldehyde gas at 177. degree C and 719. torr. After ten minutes, will there be more liquid in the beaker, less liquid, or the same amount? more less the same

Answer 1

The most volatile is cyclohexanone and the least volatile is dimethyl sulfoxide.

note - higher the slope on vapor pressure vs temp graph higher the volatility.

part 2 - to find the boiling part takes 760 torr as a reference because it corresponds to 1 atm.

draw a horizontal line from a 760 torr till all the 3 molecule graph and at which point, these lines cut from these 3 different points draw a vertical line to the x-axis to note the reading of boiling point, by doing so you will obtain

B.P of cyclohexanone to be 155-degree celsius

B.P of benzaldehyde to be 178-degree celsius

B.P of dimethyl sulfoxide to be 189-degree celsius

part 3 - by following same procedure as explained in part two we obtain boiling part of benzaldehyde to be 176 degree celsius correspond to 719 torr, and we kept benxaldehyde at 177 degree celsius which ih more than its boiling point it means it starts to boil or in other terms it will start to evaporate hence with time its volume will decrease