Chemical measurements Flashcards
Orders of magnitude
(powers of ten)
SI units for
- Time
- Mass
- Electric current
- Luminous intensity
- Amount of substance
- Plane angle
- Solid angle
SI units for
- Time: second (s)
- Mass: kilogram (kg)
- Electric current: ampere (A)
- Luminous intensity: candela (cd)
- Amount of substance: mole (mol)
- Plane angle: radian (rad)
- Solid angle: steradian (sr)
Prefix
- Giga: G
- Meta: M
- kilo: k
- deci: d
- centi: c
- mili: m
- micro:
- nano: n
- pico: p
Prefix
- Giga: G (10^9)
- Meta: M (10^6)
- kilo: k
- deci: d
- centi: c
- mili: m
- micro:
- nano: n
- pico: p
Solute
minor species in a solution
Solvent
major species in a solution
Concentration
how much solute is contained in a given volume or mass
Molarity (M)
number of moles of a substance per liter of solution
mole
Avogadro’s number of atoms or molecules or ions (6.022*10^23 1/mol)
Liter (L)
volume of a cube that is 10 cm on each edge
atomic mass
atomic mass of an element is the number of grams containing Avogadro’s number of the atoms in the molecule
strong electrolyte
mostly dissociated into ions in solution
weak electrolyte
partially dissociated into ions in solution
formal concentration (F)
molarity of strong electrolyte
formula mass (FM)
“molecular mass” of a strong electrolyte = sum of atomic masses in the formula
molality (m)
concentration = (number of moles of a solute)/(kilogram of solvent)
If no evaporation, do molality change with temperature?
No because m=concentration of masses
masses of solute & solvent X change when no evaporation
Do molarity change with temperature?
volume solution increase when heated
M = mol/V
weight percent (wt%)
percentage of a component in a mixture or solution
wt% = 100*(mass of solute)/(mass of total solution or mixture)
volume percent (vol%)
volume percent = 100*(volume of solute)/(volume of total solution)
