Chapter 1 - Chemical Measurements

10

orders of magnitude are measured in powers of __

nanoelectrode

measures neurotransmitter molecules released by a single nerve cell in response to a chemical stimulus; the tip of the instrument is smaller than a single cell

SI

fundamental units (base units) from which all other units are derived

6.022×10^-23 units/mol

Avogadro’s number

tera (T)

10^12

giga (G)

10^9

mega (M)

10^6

kilo (k)

10³

hecto (h)

10²

deca (da)

10^1

deci (d)

10^-1

centi (c)

10^-2

milli (m)

10^-3

micro (u)

10^-6

nano (n)

10^-9

pico (p)

10^-12

femto (f)

10^-15

4.184

1 calorie (cal) = ________J

1.609

1 mile = _______km

0.4536

1 pound = _______kg

solution

homogeneous mixture of two or more substances

solute

minor species in solution

solvent

major species in solution

atomic mass

number of grams of an element containing Avogadro’s number of atoms

molecular mass

sum of atomic masses of atoms in a molecule; number of grams of an element containing Avogadro’s number of molecules

formula mass

“molecular mass” of a strong electrolyte

concentration

quantity per unit volume (or mass)

molarity (M)

number of moles of a substance per liter of solution

molality (m)

number of moles of a substance per kilogram of solvent

electrolyte

substance that dissociates into ions in a solution

formal concentration

the molarity of a substance if it were not converted into other species in solution

weight percent

mass of the solute divided by the mass of the total solution/mixture multiplied by 100

volume percent

volume of solute divided by volume of total solution/mixture multiplied by 100

parts per million

mass of substance divided by mass of sample multiplied by 10^6

parts per billion

mass of substance divided by mass of sample multiplied by 10^9

distillation

water is boiled to separate it from less volatile impurities, vapor is condensed and collected in a clean contaier

deionization

water is passed through a column that removes ionic impurities, nonionic impurities remain in the water

gravimetric analysis

measures the mass of a substance to complete the analysis

volumetric analysis

measures the volume of material needed to react with analyte

limiting reagent

species that gets completely consumed first in a reaction