ACS ORGANIC CHEMISTRY EXAM 2025/2026
SPRING-SUMMER QUESTIONS AND ANSWERS
GRADED A+
Why should you vent the separatory funnel periodically when preforming an
extraction involving organic solvents?
Mixing increases the evaporation of volatile organic solvents creating pressure in
the closed space of a separatory funnel.
How much anhydrous magnesium sulfate is required to dry a diethyl ether solution
after preforming extractions involving water?
Enough such that some powder remains free flowing in solution with swirling
without clumping.
Why is sodium benzoate more soluble in water than benzoic acid?
Sodium benzoate is more soluble in water than benzoic acid because sodium
benzoate has an ionic bond, while benzoic acid has a hydrogen bond. Ionic bonds
are more soluble in water than hydrogen bond.
Why is biphenyl more soluble in diethyl ether than water?
,Biphenyl is more soluble in diethyl ether than water, because biphenyl is a non-
polar compound, which furthermore makes it insoluble in water. Diethyl ether on
the other hand is non-polar as well, which allows biphenyl to dissolve in it.
What solvent (diethyl ether or water) would glucose (shown below) be most
soluble in? Briefly explain why?
Glucose would be most soluble in water because of its polarity. Diethyl ether is
non-polar compound while glucose is a polar compound. According to the "like
dissolves like" principle, glucose is unable to dissolve in diethyl ether.
Which has a higher vapor pressure hexane or nonane?
hexane
Which should have a higher boiling point hexane or nonane?
nonane
Simple distillation is more effective when there is a __ difference between the
boiling points of the two compounds.
large
, In a distillation of a hexane/nonane mixture, which compound will predominate in
the first drops of distillate?
hexane
Near the end of a distillation of hexane/nonane mixture, which compound will
predominately remain in the boiling flask?
nonane
Why is it important to have a boiling chip present in the boiling flask when
distilling liquid mixtures?
It is important to have a boiling chip present in the boiling flask, because the
presence of the boiling chip allows the liquid mixture to evenly heat and to help
convert liquid to gas.
What role does the steel wool serve in the fractional distillation setup used during
the experiment?
The steel wool is put in place in order to increase the surface area. By increasing
the surface area in the column, it allows for multiple condensation and evaporation
cycles to occur, therefore explaining why fractional distillation is more effective.
SPRING-SUMMER QUESTIONS AND ANSWERS
GRADED A+
Why should you vent the separatory funnel periodically when preforming an
extraction involving organic solvents?
Mixing increases the evaporation of volatile organic solvents creating pressure in
the closed space of a separatory funnel.
How much anhydrous magnesium sulfate is required to dry a diethyl ether solution
after preforming extractions involving water?
Enough such that some powder remains free flowing in solution with swirling
without clumping.
Why is sodium benzoate more soluble in water than benzoic acid?
Sodium benzoate is more soluble in water than benzoic acid because sodium
benzoate has an ionic bond, while benzoic acid has a hydrogen bond. Ionic bonds
are more soluble in water than hydrogen bond.
Why is biphenyl more soluble in diethyl ether than water?
,Biphenyl is more soluble in diethyl ether than water, because biphenyl is a non-
polar compound, which furthermore makes it insoluble in water. Diethyl ether on
the other hand is non-polar as well, which allows biphenyl to dissolve in it.
What solvent (diethyl ether or water) would glucose (shown below) be most
soluble in? Briefly explain why?
Glucose would be most soluble in water because of its polarity. Diethyl ether is
non-polar compound while glucose is a polar compound. According to the "like
dissolves like" principle, glucose is unable to dissolve in diethyl ether.
Which has a higher vapor pressure hexane or nonane?
hexane
Which should have a higher boiling point hexane or nonane?
nonane
Simple distillation is more effective when there is a __ difference between the
boiling points of the two compounds.
large
, In a distillation of a hexane/nonane mixture, which compound will predominate in
the first drops of distillate?
hexane
Near the end of a distillation of hexane/nonane mixture, which compound will
predominately remain in the boiling flask?
nonane
Why is it important to have a boiling chip present in the boiling flask when
distilling liquid mixtures?
It is important to have a boiling chip present in the boiling flask, because the
presence of the boiling chip allows the liquid mixture to evenly heat and to help
convert liquid to gas.
What role does the steel wool serve in the fractional distillation setup used during
the experiment?
The steel wool is put in place in order to increase the surface area. By increasing
the surface area in the column, it allows for multiple condensation and evaporation
cycles to occur, therefore explaining why fractional distillation is more effective.
