Question

T/F

(1) Additives added to ethanol will have the same effect on boiling point as the same amount of additives added to water Ethanol changes its solution boiling point with additive mass fraction of 0.15 more than water changes its boiling point with a mass fraction of 0.25 If the activity coefficient of solute A in a solution is equal to 1, A has little to no preference to other molecules around it in solution It is likely that flavors that are more soluble in oily layers than aqueous layers have activity coefficients more than 1 in the aqueous part _ The activity of water in solution is almost always the same as its concentration The activity of water in a protein solution is likely greater than the activity of water in the same concentration of dissolved hydrocarbon gases A BET plot for beef jerky, for example, depicts how strong water is held to the beef in different parts of the jerky Different foods attract water with different affinities; there are at least a half dozen different "equations of state" that relate the activity of water to sorption parameters X,a, and even temperature shown Osmotic coefficients can be measured in a simple U-tube system - at least to get a relationship between different types of substances in the same solvent Osmotic pressure is related to activity coefficients in a complex polynomial format only applicable to dilute aqueous solutions at standard temperature and pressure Molality is the same as Molarity if the number of functional groups is the same A 0.2 molar solution of sucrose is the same as a 0.4 molal solution of sucrose Dehydration of foods inactivates pathogens, including when they are added to soup Sublimination is the change in phase from solid to gas without first becoming a liquid

Answer 1

Statement 1 is False.

Explanation: Water boils at 100 ^oC, whereas ethanol boils at 78.37 ^oC.

Statement 2 is True.

Explanation: $\Delta$Tb = Kb*mass fraction

For water: $\Delta$Tb = 0.512 ^oC * 0.25

i.e. $\Delta$Tb = 0.128 ^oC

For ethanol: $\Delta$Tb = 1.22 ^oC * 0.15

i.e. $\Delta$Tb = 0.553 ^oC

Here, 0.553 ^oC is more than 0.128 ^oC.