JMU CHEM 120 FINAL EXAM QUESTIONS AND ANSWERS 100% PASS

JMU CHEM 120 FINAL EXAM
QUESTIONS AND ANSWERS 100% PASS



Scientific notation - ANS a way of expressing large & small #s in a more compact/precise way,
n x 10^n


Units: G - ANS Giga, 1 x 10 ^9


Units: M - ANS Mega, 1 x10^6


Units: k - ANS Kilo, 1 x10^3


Units: h - ANS Hecto, 1 x10^2


Units: D - ANS Deca, 1 x101


Units: d - ANS Deci, 1 x10^-1


Units: c - ANS Centi, 1 x10^-2


Units: m - ANS Mili, 1 x10-3


Units: μ - ANS Micro, 1 x10-6

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, Units: n - ANS Nano, 1 x10-9


Units: p - ANS Pico, 1 x10-12


Density - ANS d=m/v


Density units - ANS g/mL or g/cm^3 (1cm^3= 1 mL)


Specific gravity - ANS density ratio between a substance and a standard, usually H2O, NO
UNITS


Just divide density ratio by 1.00g/mL


Parts per million (ppm) - ANS Number of parts of a chemical found in 1 million parts of a
particular gas, liquid, or solid.


1mg/L (LIQUID) 1mg/kg (SOLID)


Parts per billion (ppb) - ANS Number of parts of a chemical found in 1 billion parts of a
particular gas, liquid, or solid.


1μg/L (LIQUID) 1μg/kg (SOLID)


Toxicity - ANS The degree to which a substance is biologically harmful. Every chemical can be
safe OR toxic, depending how much is in the body.


LD50 - ANS Medium lethal dose, amount needed to kill 50% of a test population.




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