ml each of water and HCl conc. only after vigorous
reaction subsides. For Cu, Pb, Sn and fusible
alloys add 10 ml of HCl conc. and a few drops of
HNO3 (just sufficient but no more) [6].
2.4.2. Note 2
If there is any insoluble matter left, filter it off
through a medium-texture filter paper and wash
the paper thoroughly with HCl.
2.4.3. Note 3
If As is present, transfer the analyte solution to
a distillation flask in a smaller size, and distil till
the temperature of the vapor in the flask reaches
108°C under standard pressure.
2.4.4. Note 4
Its optimum amount is 9 ml for Pb, Sn and
fusible alloys; 13 ml for Cu alloys; 17 ml for Ti
alloys; 30 ml for Al–Sn alloys. Sometimes heating
is necessary, e.g. to complex Cr(III). If the sample
contains ]35% of Sn; or Mo or V or both, dilute
its solution to a definite volume. For the determination
take therefrom an appropriate aliquot (to
which 3 ml of tartaric acid solution should be
added) estimated after analyzing the other major
elements.
2.4.5. Note 5
Omit its addition whenever colored species is
present.
2.4.6. Note 6
Omit or reduce its addition if the analyte solution
contains Al. This addition may raise the pH
of the analyte solution.
2.4.7. Note 7
If V is present, add 10 ml of ethanol to the
filtrate.
2.4.8. Note 8
Its amount depends on that of the species to be
masked.
2.4.9. Note 9
Its amount depends on: (a) mg of Sn(IV) to be
determined; (b) mg of Mo or V or both in the
ml each of water and HCl conc. only after vigorous
reaction subsides. For Cu, Pb, Sn and fusible
alloys add 10 ml of HCl conc. and a few drops of
HNO3 (just sufficient but no more) [6].
2.4.2. Note 2
If there is any insoluble matter left, filter it off
through a medium-texture filter paper and wash
the paper thoroughly with HCl.
2.4.3. Note 3
If As is present, transfer the analyte solution to
a distillation flask in a smaller size, and distil till
the temperature of the vapor in the flask reaches
108°C under standard pressure.
2.4.4. Note 4
Its optimum amount is 9 ml for Pb, Sn and
fusible alloys; 13 ml for Cu alloys; 17 ml for Ti
alloys; 30 ml for Al–Sn alloys. Sometimes heating
is necessary, e.g. to complex Cr(III). If the sample
contains ]35% of Sn; or Mo or V or both, dilute
its solution to a definite volume. For the determination
take therefrom an appropriate aliquot (to
which 3 ml of tartaric acid solution should be
added) estimated after analyzing the other major
elements.
2.4.5. Note 5
Omit its addition whenever colored species is
present.
2.4.6. Note 6
Omit or reduce its addition if the analyte solution
contains Al. This addition may raise the pH
of the analyte solution.
2.4.7. Note 7
If V is present, add 10 ml of ethanol to the
filtrate.
2.4.8. Note 8
Its amount depends on that of the species to be
masked.
2.4.9. Note 9
Its amount depends on: (a) mg of Sn(IV) to be
determined; (b) mg of Mo or V or both in the
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