NOTE:..
Greg Anderson
Bates College
How to Make Simple Solutions and Dilutions
click here
!
!
Unit Definitions
milligram "
" #$
#%%%
gram "
kilogram "
" #%%%
#%'
)'
mole " (%)' !#%
molarity "
molar " "
#%&'
eg
)*
millimole " #$
#%%%
millimolar "
"
)%$
#%%%" %%)
$"
$"
)*
eg
)%
1. Simple Dilution (Dilution Factor Method)..
simple dilution
unit volume
solvent +
factor
+
,
!
#.
*
!
/
0
#
12
-
*0
dilution
,
!
#
#1 2" *"
#.,
#.
'%%
!#
)33
4
!
-
0
50
!
)%5
667
,
8
0
50
!
). #5
)%5 667
667
#3
)%5 667
!
2. Mixing parts or volumes..
!
0
#
'
'
0
9
!
!
#
!#
'
!
!
7
!
.4
#.
'
!
8
#.
'
!
7
0
0
# 4
0
:4
0
3. Serial Dilution..
serial dilution
+
;<
total dilution factor
product
;- " ;-#=;-)=;-' etc
!
+
etc
,
4
/
.4
>4
? ?@9 )%#
,
33%A " #.
#%%
33
33
the 1:100 dilution
#.
#%%=#%%" #.
#%%%% B
= #%%%% " #.
#%%%%%%
less
three step #.
#%%
#% A
of
#
4
!
#.
#%%
,
4. Making fixed volumes of specific concentrations from liquid reagents: V1C1=V2C2..
C
D
+
+
!
eg
,
+
.
V = volume C = concentration;
V1C1=V2C2
!
#.6
V1
V1 "
C1 " #%%
V2 "
C2 "
'
)%% A " C2
)*
)%%A
#%%
$
$
" V2
This is your unknown.
D
$
>
C#" C)!7) $7#
C#" %)
!)*
$
" )%%A " %)
" )*
$
.
$#%%
$
" C1
9
" %%*
6
A
" *%A
*%A
)*
#*%A
)%%
$
5. Molar solutions (unit = M = moles/L)..
molarity
# formula weight -E
-
6
#
#%
#%
+
#%
$
molecular weight
!
#.To prepare a liter of a simple molar solution from a dry reagent:
formula weight
.
7
-E " #32' $
#32' $
!
=%#*
F
%#*
$ " )3#2* $
).To prepare a specific volume of a specific molar solution from a dry reagent:
-E
"
E
$
#G% $
)*
%%)*
8
%#*
)*
:
H
$
"
>
H
H
"
" %%)* =%#*
H
" %(I*
6
)*
$ =-E
=
$ =#G% $
$ =-E
%#*
$
$
%(I*
)*
6. Percent Solutions (= parts per hundred)..
!
!
percent concentrations. E
dry mass (g) per volume
H $
#%%
"
+
#%
#%%
>
#%J < 7
<7
#%J
!
#.4
'J
+
$ <7
$ <7
'%
<7
#%%
8
#%%
#J
$
#%%
!
).,
#) = '*%
6
'*%
$
#%%
2)
!
6
$ <7
" #) !' *" 2)
<7
'.
%%*= #*
#)J
'*%
#*
$
#%%
%%%I*
%%*J
" %%%I*
$
<?'
I*
<?'
#*
volume per volume i e
liquid reagents
E
H
$
#%%
!
2.4
I%J
$
! I%
#%%J
'%
#%%
!
*.,
)#*
= 3#)
6
! #3(#
3#)
$
#%%
,
)#*J
$,
5&#%%
" #3(#
5&#%%
I#*3
)#*J
7. Conversions from % to molarity and from molarity to %..
To convert from % solution to molarity
$
#%
Molarity = (% solution) * 10
Xxxxx
FW
!
(.,
K(* $
#%%
(*J
-E " ')*(
=#%L$')*( $ " %#33(
To convert from molarity to percent solution
#%.
-E
% solution = molarity * FW
xxxxxxxxxx10
!
I. 7
.
%%%2*
-E #IGI
$
K
%%%2*
$ =#IGI $
L$#%" %%GJ