Appendix 3: result calculations, Titra lab, Volume determination – Hach-Lange TITRALAB 860_865 Reference Manual User Manual

Page 235: Direct titration

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Titra

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TitraLab 860 and 865 Reference Manual

Page 235

Appendix 3: Result calculations

Titration ends with determination of several volumes, corresponding to the different equivalent
points: Vepi.

The blank volumes are Bi.

Calculations are based on these volumes and you determine with which volume (or which
equivalent point) you want to work. In fact, in a method, you can have at least as much results
as equivalent points, but it is possible to have less by choosing the desired equivalent point.

Moreover, with several equivalent points, you can choose to work with the cumulated or the
subtracted volumes (volumes between equivalences).

1. Volume determination

This volume determination does not apply for the volume calculation in the back titration mode
concerning the blank option.

2. Direct titration

If sample is expressed in volume:

If sample is expressed in weight:

If the sample is diluted, the above equations are also multiplied by Vdil/Val, to have the
concentration in the original sample.

- Vi: volume of titrant at the equivalence (ml)
- C

reag

: titrant concentration

- Vs: sample volume in ml
- ms: sample amount in g
- c: conversion factor
- Vdil: dilution volume
- Val: aliquot volume

Cumulated volume

Subtracted volume

Normal

V1 = Veq1
Vi = Veqi

V1 = Veq1
Vi = Veqi - Veq(i-1)

With
blank

For EP titration: Vi = Veqi - Bi
For IP titration and B applied to eq2:
V1 = Veq1
V2 = Veq2 - B
Vi = Veqi - B

For EP titration:

Vi = Veqi - Veq(i-1) - Bi

For IP titration and B applied to eq2:

V1 = Veq1
V2 = Veq2 - Veq1 - B
Vi = Veqi - Veq(i-1)

Csmp

Vi

Creag

×

Vs

----------------------------

c

×

=

Csmp

Vi

Creag

×

m

s

----------------------------

c

Ч

=

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