USNCO Exams - Reference Page

Below is the standard information that is provided as reference for all USNCO exams. No additional information may be accessed while taking any USNCO exam.

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Abbreviations and Symbols

Full Name Abbreviation/Symbol
amount of substance n
ampere A
atmosphere atm
atomic mass unit u
Avogadro constant NA
Celsius temperature °C
centi– prefix c
coulomb C
density d
electromotive force E
energy of activation Ea
enthalpy H
entropy S
equilibrium constant K
Faraday constant F
free energy G
frequency ν
gas constant R
gram g
hour h
joule J
kelvin K
kilo– prefix k
liter L
measure of pressure mm Hg
milli– prefix m
molal m
molar M
molar mass M
mole mol
Planck’s constant h
pressure P
rate constant k
reaction quotient Q
second s
speed of light c
temperature, K T
time t
vapor pressure VP
volt V
volume V
year y


R = 8.314 J mol–1 K–1
R = 0.08314 L bar mol–1 K–1
F = 96,500 C mol–1
F = 96,500 J V–1 mol–1
NA = 6.022 x 1023 mol–1
h = 6.626 x 10–34 J s
c = 2.998 x 108 m s–1
0 °C = 273.15 K
1 atm = 1.013 bar = 760 mm Hg
Specific heat capacity of H2O = 4.184 J g–1 K–1


E = Eo(RT/nF) x lnQ

lnK = (—ΔHo/R) x (1/T) + constant

ln(k2/k1) = (Ea/R) x ((1/T1) — (1/T2))


Periodic Table of the Elements

Thank you to the Olympiad Examinations Task Force

  • Seth N. Brown, Chair, University of Notre Dame, Notre Dame, IN
  • James Ayers, Colorado Mesa University, Grand Junction, CO
  • Jerry Bell, Simmons University, Boston, MA (retired)
  • Mark DeCamp, University of Michigan, Dearborn, MI (retired)
  • James Dohm, Vanderbilt University, Nashville, TN
  • Xu Duan, Holton-Arms School, Bethesda, MD
  • Valerie Ferguson, Moore HS, Moore, OK
  • Julie Furstenau, Thomas B. Doherty HS, Colorado Springs, CO (retired)
  • Kimberly Gardner, United States Air Force Academy, CO
  • Paul Groves, South Pasadena HS, South Pasadena, CA
  • Nicolas Hamel, Clackamas Community College, Oregon City, OR
  • David W. Hostage, Taft School, Watertown, CT
  • John Kotz, State University of New York, Oneonta, NY (retired)
  • Sarah Leite, Hopkins School, New Have, CT
  • Michael A. Morgan, Francisco Bravo Medical Magnet HS, Los Angeles, CA
  • Jane Nagurney, Scranton Preparatory School, Scranton, PA (retired)
  • Sheila Nguyen, Claremont Graduate University, Claremont, CA

Thank you to the Olympiad Laboratory Practical Task Force

  • Kelli Slunt, Chair, University of Mary Washington, Fredericksburg, VA
  • Payton Bailey, University of Mary Washington, Fredericksburg, VA
  • Jesse Bernstein, Miami Country Day School, Miami FL (retired)
  • Alexsandra DaSilva, SUNY, Binghamton, NY
  • Myra Halpin, NC School of Science & Mathematics, Durham, NC (retired)
  • Nicolas Hamel, Clackamas Community College, Oregon City, OR
  • Innocent Pumure, University of Central Missouri, Warrensburg, MO
  • Lawrence Wilkinson, ExxonMobil, Baton Rouge, LA