Gravimetric Factor Research Articles

Application of the uranyl salt method to the determination of arsenic by the oxygen flask technique

A modified oxygen flask technique is described for determining As in organic compounds, the conventional Pt supports being replaced by Al spirals or steel gauzes, which resist attack by As during the vigorous combustion. A favorable gravimetric factor is ensured by the quantitative precipitation of the As as ammonium uranyl arsenate and subsequent ignition, under controlled conditions, to the black triuranium octaoxide, U/sub 3/O/sub 8/. Phosphate and vanadate form similar insoluble ammonium uranyl salts, and the method is not directly applicable to organic compounds containing these elements without prior separation. (auth)

A highly accurate and precise method for the assay of chromium metal and chromium(III) oxide

A method capable of a precision of 3 to 5 parts in ten thousand has been developed for the routine assay of high purity chromium metal and chromium trioxide. Use has been made of the favourable gravimetric factor of ferrous ammonium sulfate and of an amperometric end-point. Comparison with the arsenic trioxide method was made.

Hypophosphorous Acid as Gravimetric Reagent for Scandium

During a search for a more specific gravimetric determination of scandtum, it was found that hypophosphorous acid prcduced a weighable precipitate of scandinm hypophosphite. A low gravimetric factor, combined with some improvement in selectivity over existing methods, indicated a useful reagent. The granular precipitate was easily transferred, washed, and dried. Qanantitative recovery was obtained in the range from 0.1 to 1.0 mmole of scandium. (anth)

Measurements of tidal gravity and load deformations on Unst (Shetlands)

The tidal gravimetric factor due to the elastic yielding of the Earth has been determined by gravimetric measurements on Unst (Shetland Islands), extending over the time of one month. Its corrected value isG=1.205±0.03. The influence of applying different methods of harmonic analysis, and the effects of ambient temperature and pressures and of the sea tides on the gravimetric results are discussed. No significant difference inG for semi-diurnal and diurnal tides remains after the necessary corrections have been made. The amplitude of the semidiurnal load depression is about 2 cm and it is shown that the more distant North Atlantic tides have a greater effect than the regional tides near the Shetlands. An approximate calculation gives 4.3×1011 CGS-units as the mean rigidity of the part of the Earth's crust yielding to the maritime loading differences in this region.

TIDAL GRAVITY OBSERVATIONS AT WINSFORD (CHESHIRE)

Summary Tidal observations have been performed in the I. C. I. Salt Mine at Winsford. The gravimetric factor has been determined both for the overall values and the principal harmonic constituents. Its value is G= 1.20 ± 0.04. The results are compared with former measurements.