CH5
Dimensional Analysis
Instructor: J.T.,
P: 1
Nurses use three systems of measurements:
1)
2)
3)
The Metric system
The Apothecary system
The English (household) system
1) The Metric System:
a) Weight (mcg, mg, g, Kg)
b) Volume (mL, L, cc)
c) Length (m, cm, mm)
2)
The Apothecary system:
a) Weight (grain [gr], dram [dr], ounce [oz], Pound
[Ib])
b) Volume (fluid dram [fdr], quart [qt], gallon [gal])
3)
The English (household) system
a) Weight (ounce [oz], Pound [Ib])
a) Volume (teaspoon, Tablespoon, Cup, quart [qt],
gallon [gal])
b) Length (Inch [in])
You should memorize some of the metric prefixes:
FACTOR
1.0E+24
1.0E+21
1.0E+18
1.0E+15
1.0E+12
1.0E+9
1.0E+6
1.0E+3
1.0E+2
1.0E+1
1.0E-1
1.0E-2
1.0E-3
1.0E-6
1.0E-9
1.0E-12
1.0E-15
1.0E-18
1.0E-21
1.0E-24
In number
1 000 000 000 000 000 000 000 000
1 000 000 000 000 000 000 000
1 000 000 000 000 000 000
1 000 000 000 000 000
1 000 000 000 000
1 000 000 000
1 000 000
1 000
100
10
0.1
0.01
0.001
0.000 001
0.000 000 001
0.000 000 000 001
0.000 000 000 000 001
0.000 000 000 000 000 001
0.000 000 000 000 000 000 001
0.000 000 000 000 000 000 000 001
In Text
septillion
sextillion
quintillion
quadrillion
trillion
billion
million
SI
PREFIX
SI
SYMBOL
yottazettaexapetateragigamega-
Y
Z
E
P
T
G
M
thousand
kilo-
k
hundred
ten
hectodeca-
h
da
tenth
hundredth
thousandth
millionth
decicentimillimicro-
d
c
m
µ
billionth
trillionth
quadrillionth
quintillionth
sextillionth
septillionth
nanopicofemtoattozeptoyocto-
n
p
f
a
z
y
CH5
Dimensional Analysis
Instructor: J.T.,
P: 2
Dimensional Analysis:
⎛
you need ⎞
⎟⎟ = (Units you need
⎝ same as unit you have ⎠
( Units you have ) × ⎜⎜ same as Units
⎛
( you haveUnit : A) × ⎜⎜ Units X
⎝ Unit A
×
)
Units Y Units Z ⎞
⎟ = ( you get Unit : Z )
×
Units X Units Y ⎟⎠
{Conversion Factors}
Example 2: (Lab manual, page 9)
⎛ 10 −3 g 15 gr ⎞
⎟⎟ =
( 2 mg darvocet ) × ⎜⎜
×
1g ⎠
⎝ 1 mg
{Units you have}
{Conversion Factors}
0.03 gr
{Units you need}
Scientific Notation (SN):
Large number:
Distance between Sun & Earth: 150,000,000,000 meters or 1.5 × 1011 m
Small Number:
Distance between proton and electron in a hydrogen atom: 0.000,000,000,053 meters or
5.3 × 10-11 m
Concentration:
Sugar
salute
Water
solvent
™ Concentration: mass of salute / volume of solvent
™ Concentrated & Dilute?
™ Concentrated units: g/L
%( W/V) = gram of solute per 100 mL of solution
™ C1 V1 = C2 V2
See Example 7.
mixed
solution