light scattering - 2024 ACF Nationals

Question

A method of measuring zeta potential involves observing this process in an electric field. For 10 points each:

[10m] Name this process surveyed from multiple angles in “dynamic” and “static” methods of determining a polymer’s radius of gyration. A Zimm plot depicts the change in intensity due to this process.

ANSWER: light scattering [or word forms of scattered; accept dynamic light scattering, static light scattering, multi-angle light scattering, DLS, SLS or MALS]

[10e] This quantity’s distribution can be extracted from the autocorrelation of scattering intensity over time. This quantity can be measured in daltons.

ANSWER: molecular weight [accept molecular mass or molar mass; prompt on size or length]

[10h] The y-intercept of a Zimm plot can be divided into a term for weight and a term for this quantity times concentration. The BWR equation of state requires more constants to express this quantity than its relatives, but it only takes one Mayer f-function to express this quantity exactly.

ANSWER: second virial coefficient [or B2; or A2; prompt on virial coefficients]

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Data

Team	Opponent	Part 1	Part 2	Part 3	Total
Brown	Ottawa	10	10	0	20
Chicago A	Arizona State	10	10	10	30
Chicago B	Harvard	0	10	0	10
Columbia B	Chicago D	0	10	0	10
Cornell B	Georgia Tech	0	0	0	0
Duke	Johns Hopkins	0	10	0	10
Illinois	Chicago C	10	10	10	30
Indiana	Iowa State	10	10	0	20
Kentucky	Berkeley B	0	0	0	0
Maryland	Truman State	0	0	0	0
Minnesota A	McGill	0	10	0	10
North Carolina A	Florida	0	10	10	20
North Carolina B	Toronto B	0	10	0	10
Rutgers	NYU	0	10	0	10
South Carolina	Yale A	0	0	0	0
Stanford	Purdue	10	10	10	30
Texas	WUSTL B	0	10	0	10
Vanderbilt	Penn	0	0	0	0
Virginia	Toronto A	0	10	0	10
WUSTL A	Minnesota B	10	10	10	30
Waterloo	Berkeley A	10	10	0	20
Yale B	Northwestern	0	10	0	10

Summary

Tournament	Edition	Exact Match?	Heard	PPB	Easy %	Medium %	Hard %
2024 ACF Nationals	04/21/2024	Y	22	13.18	77%	32%	23%