Determination of the specific gravity of a solution of uranyl nitrate
Scope
This method covers the determination of the specific gravity of a solution of uranyl nitrate to ± 0.0004
Summary of method
A known volume of the solution adjusted at a controlled temperature is weighed and compared to the weight of water measured in the same container.
Equipments
Volumetric Flask, 50-mL, class A
Water Bath, temperature controlled to ± 0.1 oC at a temperature slightly above
normal room temperature, and provided with clips for holding volumetric flasks.
Procedure
Weigh the clean, dry volumetric flask and its stopper to the nearest 0.1 mg
Fill the volumetric flask with the uranyl nitrate solution to a point close to the volume mark, using a thin stemmed funnel and a glass dropper.
Place the stoppered volumetric flask in the water bath for 30 min.
Use a finely drawn glass dropper to adjust the liquid volume to the mark
Leave the flask in the water bath an additional 10 min to make sure that the bath temperature has been reached.
Dry and weigh the flask to the nearest 0.1 mg.
Repeat step 2 up to step 6 using boiled and cooled distilled water instead of the uranyl nitrate solution.
Very accurate determinations of specific gravity require that vacuo corrections be made, but if a median correction figure in terms of grams of sample is applied to the solution weights in all cases the resulting error will not exceed 0.05%.
Sp gr = B-A + 0.0007(B-A)
C+A + 0.0010 (C-A)
B = sample plus flask in air, g
A = flask in air, g
C = water plus flask in air,g
0.007 g/g = correction factor applicable for densities of 1.3 to 1.5 and
0.0010 g/g = correction factor for water.
Precision
The limit of error at the 95% level for a singledetermination is ± 0.003%
Literature
ASTM-C799, Standard Methods for “Chemical, Mass Spectrometric, Spectrochemical, Nuclear, and Radiochemical analysis of Nuclear-Grade Uranyl Nitrate solution”
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