density - 2024 ARCADIA at BU

Question

Before doing a liquid-liquid extraction, one should verify the values of this property for the employed solvents. For 10 points each:

[10e] Name this property of the aqueous and organic layers that determines which layer sits on top. For water, this quantity is 1 gram per milliliter.

ANSWER: density [or mass density]

[10h] Unlike most organic solvents like hexanes or ethyl acetate, this dense solvent sits below the aqueous layer during an extraction. This solvent is often used to decaffeinate coffee and was once common in paint removers, but the EPA banned its use in 2019.

ANSWER: dichloromethane [or DCM or methylene chloride or CH2Cl2]

[10m] This quantity gives the equilibrium ratio of a molecule’s concentrations in the aqueous and organic layers for an extraction. A molecule’s lipophilicity is often measured by the log of this quantity for the octanol-water system.

ANSWER: partition coefficient [or distribution coefficient; prompt on D or P or K; prompt on log P or c log P]

<JZ, Chemistry>

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Summary


2024 ARCADIA at BU	2024-12-06	Y	6	11.67	100%	0%	17%
2024 ARCADIA at Duke	2024-12-06	Y	3	10.00	100%	0%	0%
2024 ARCADIA at Missouri S&T	2024-12-06	Y	2	10.00	100%	0%	0%
2024 ARCADIA Online	2025-05-17	Y	5	16.00	100%	60%	0%
2024 ARCADIA at Penn State	2024-12-06	Y	2	10.00	100%	0%	0%
2024 ARCADIA at Florida Tech	2024-12-06	Y	4	15.00	100%	50%	0%
2024 ARCADIA at UC Berkeley	2024-12-06	Y	2	15.00	100%	50%	0%
2024 ARCADIA at GT	2024-12-06	Y	5	12.00	100%	20%	0%
2024 ARCADIA at Warwick	2024-12-06	Y	5	12.00	100%	0%	20%

Data


Harvard	Bowdoin B	10	0	10
Clark House	Bowdoin C	10	0	10
Tufts A	Boston College B	10	0	10
Bowdoin A	Clark Wilson	10	0	10
BU	Tufts B	10	0	10
Yale	Amherst	10	10	20