You did not link an image of it so I can’t see the rings.
Answer:
14.9802 grams of estrogen must be added to 216.7 grams of benzene.
Explanation:
The relative lowering of vapor pressure of solution containing non volatile solute is equal to mole fraction of solute.

Where:
= Vapor pressure of pure solvent
= Vapor pressure of the solution
= Number of moles of solvent
= Number of moles of solute





Mass of 0.05499 moles of estrogen :
= 0.05499 mol × 272.4 g/mol = 14.9802 g
14.9802 grams of estrogen must be added to 216.7 grams of benzene.
Explanation:
i guess it's through thousands of research and experiments they conducted
The right answer is 271.78 degrees for cyclohexane.
For each liquid there is a precise relationship between pressure and boiling temperature, we can define the boiling temperature as the moment when the first bubble of vapor appears on the surface of a liquid.