4th prac)cal class ASSAY – VOLUMETRIC ANALYSIS
NAME: Lídia Prieto García
SAMPLE: Sodium chloride
1) IDENTIFICATION REACTIONS OF IONS
2) AgNO3 (aq) + NaCl (aq) —> AgCl (s) + NaNO3 (aq)
- CATIONS (describe briefly reac-ons):
Na + AgNO3 —> NaNO3 (aq) no precipitate
Na + HNO3 —> NaNO3 (aq) no precipitate
Ag+ (waste) + SCN- —> AgSCN (s) The excess of thiocyanate re<cts with Fe 3+ to form a dark red
complex, When the silver ions have reacted.
Fe 3+ + SCN —> [FeSCN]2+
- ANIONS (describe briefly reac-ons):
Cl- + AgNO3 —> AgCl (s) precipitate
2) ASSAY
Volumetric solu^ons: 0’1M silver nitrate
Titre of volumetric solu^ons: 0’9998
CALCULATION PROCEDURE:
Titra^on No. m [g] (4 decimal places) Consump^on of VS [ml] ASSAY
1. 0.9968 8.21 98.8345
2. 0.9954 8.12 99.4965
3. 1.0045 8.45 96.6960
4. 1.0354 7.89 97.0027
Average 98.0074
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4th prac)cal class ASSAY – VOLUMETRIC ANALYSIS
STATISTICAL EVALUATION:
Range: R = 2.8005
Standard devia^on (es-mated from range): sd = 1.3602
Rela^ve standard devia^on: RSD = 1.3879
CONCLUSION (does your sample meet/not meet Ph. Eur): The sample do not meet Ph. Eur, because
the value 98.0074 is not in the interval 99.0-100.5.
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