6. Calculate sample concentration, C
s
x:
V
t
x V
f
o
C
s
x
= (C
s
o)
V
f
x V
t
o
Where:
C
s
x
= sample concentration
C
S
o
= fluoride standard concentration (0.1M)
V
t
x
= volume of titrant added in unknown sample titration
at endpoint
V
t
o
= volume of titrant added in standardization titration
at endpoint
V
f
x
= volume of sample used in sample titration (25 mL)
V
f
o
= volume of standard used in standardization titration
(25 mL)
Figure 2
Titration of 0.114 M F
-
with 0.1 M La(NO
3
)
3
23
-100
-50
0
50
100
5
10
15
20
25
titrant volume (mL)
electrode
potential
(mV)
Содержание 96-09
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