Plumes are typically formed when a continuous source of buoyancy is supplied at a localized source. We studied laminar plumes where buoyancy is supplied by an autocatalytic chemical reaction: The iodate-arsenous acid (IAA) reaction. The nonlinear kinetics of the IAA reaction produces a sharp propagating front at which buoyancy is produced by exothermicity and compositional change. When the reac...

Sendroy (l-3) pointed out in his original papers on the determination of chloride by the reaction, AgI03 + Cl% AgCl + 103, that the 103formed reduces the AgI03 solubility to a negligible value in analyses of plasma, and of urines except those with unusually little chloride. Sendroy ((1) Fig. 2) gave a curve of corrections for AgI03 solubility at 20-25”, for use in. analyses of low chloride urin...

In the present investigation, lead iodate crystals were grown in silica gel at ambient temperature. The effect of various parameters like gel concentration, pH of gel, gel ageing, concentration of the reactants on the growth of these crystals were studied. Good quality crystals having different morphologies and habits were obtained. Some of These crystals were opaque and some were translucent.

We demonstrate a novel mechanism for controlling the frequency, amplitude, and existence of chemical oscillations. Using a ferrocyanide-iodate-sulfite reaction, we show that a chemical buffer can increase or decrease the frequency of oscillations. Furthermore, the same buffer can completely suppress or, conversely, induce oscillations when added to the appropriate composition. This simple buffe...

We report experimental observations of the convection-driven fingering instability of an iodate-arsenous acid chemical reaction front. The front propagated upward in a vertical slab; the thickness of the slab was varied to control the degree of instability. We observed the onset and subsequent nonlinear evolution of the fingers, which were made visible by a pH indicator. We measured the spacing...

Instabilities in propagating fronts of the iodate-arsenous acid reaction are predicted by an empirical rate-law model. The planar front loses stability when the ratio of the reactant diffusivity to the autocatalyst diffusivity exceeds a critical value. The relative diffusivities can be altered by introducing a reagent that reacts specifically with the autocatalyst to form an immobile complex. E...

Transparent single crystals of a new iodate Cs5[Sc2(IO3)9](IO3)2 were synthesized under mild hydrothermal conditions. X-ray diffraction crystal was used to determine the large structure with 52 independent atoms, sp. gr. P21/c. The building blocks [Sc(IO3)6]3− Sc octahedra and six (IO3) groups are condensed into framework; contains additional isolated groups. Large Cs cations occupy holes form ...