Rubidium hydrogen sulfate, sometimes referred to as rubidium bisulfate, is the half neutralized

rubidium Rubidium is the chemical element with the symbol Rb and atomic number 37. It is a very soft, whitish-grey solid in the alkali metal group, similar to potassium and caesium. Rubidium is the first alkali metal in the group to have a density higher ...

salt Salt is a mineral composed primarily of sodium chloride (NaCl), a chemical compound belonging to the larger class of salts; salt in the form of a natural crystalline mineral is known as rock salt or halite. Salt is present in vast quantitie ...

sulfuric acid Sulfuric acid (American spelling and the preferred IUPAC name) or sulphuric acid ( Commonwealth spelling), known in antiquity as oil of vitriol, is a mineral acid composed of the elements sulfur, oxygen and hydrogen, with the molecular formu ...

. It has the formula RbHSO₄.

Synthesis

It may be synthesised with water and a stoichiometric amount of rubidium disulfate. Reaction takes place where there is no humidity:S. B. Rasmussen, H. Hamma, K. M. Eriksen, G. Hatem, M. Gaune-Escard, R. Fehrmann: "Physico-chemical properties and transition metal complex formation in alkali pyrosulfate and hydrogen sulfate melts". VII International Conference on Molten Slags Fluxes and Salts, The South African Institute of Mining and Metallurgy, 2004
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(PDF; 661 kB) : + H2O -> 2RbHSO_4 There is another method of creation. It is similar to the synthesis of

sodium sulfate Sodium sulfate (also known as sodium sulphate or sulfate of soda) is the inorganic compound with formula Na2SO4 as well as several related hydrates. All forms are white solids that are highly soluble in water. With an annual production of 6 milli ...

and

potassium sulfate Potassium sulfate (US) or potassium sulphate (UK), also called sulphate of potash (SOP), arcanite, or archaically potash of sulfur, is the inorganic compound with formula K2SO4, a white water-soluble solid. It is commonly used in fertilizers, pro ...

. This reaction requires

rubidium chloride Rubidium chloride is the chemical compound with the formula RbCl. This alkali metal halide salt is composed of rubidium and chlorine, and finds diverse uses ranging from electrochemistry to molecular biology. Structure In its gas phase, RbCl is d ...

and a little bit of warm sulfuric acid. Some

hydrogen chloride The compound hydrogen chloride has the chemical formula and as such is a hydrogen halide. At room temperature, it is a colourless gas, which forms white fumes of hydrochloric acid upon contact with atmospheric water vapor. Hydrogen chloride ga ...

is also produced during the reaction. : + RbCl -> + HCl

Properties

It is a

hygroscopic Hygroscopy is the phenomenon of attracting and holding water molecules via either absorption or adsorption from the surrounding environment, which is usually at normal or room temperature. If water molecules become suspended among the substance ...

compound. It has a

monoclinic In crystallography, the monoclinic crystal system is one of the seven crystal systems. A crystal system is described by three vectors. In the monoclinic system, the crystal is described by vectors of unequal lengths, as in the orthorhombic s ...

crystal structure, its structure is P2₁/n. Dimensions of the unit cell are: a = 1440 pm, b = 462.2 pm, c = 1436 pm and β = 118.0°. Its crystals are isomorphs with ammonium hydrogen sulfate crystals.J. P. Ashmore, H. E. Petch: "The Structure of RbHSO₄ in its Paraelectric Phase" in ''Can. J. Phys'' 1975, ''53''(24), S. 2694-2702. Its standard enthalpy is −1166 kJ/mol.L. A. Cowan, R. M. Morcos, N. Hatada, A. Navrotsky, S. M. Haile: "High temperature properties of Rb₃H(SO₄)₂ at ambient pressure: Absence of a polymorphic, superprotonic transition" in ''Solid State Ionics'' 2008, ''179'', S. 305-313
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(PDF; 837 kB) During its dissolution in water, there is 15.62 kJ/mol energy produced.M. de Forcrand: "Sur les chlorures et sulfates de rubidium et de caesium" in ''Compt. Rend. Hebd.'' 1906, ''143'', S. 98
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/ref> After warming up it decomposes to rubidium disulfate and water:R. Abegg, F. Auerbach: "Handbuch der anorganischen Chemie". Verlag S. Hirzel, Bd. 2, 1908. S. 43
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/ref> :2RbHSO4 -> Rb2S2O7 + H2O Like

potassium Potassium is the chemical element with the symbol K (from Neo-Latin ''kalium'') and atomic number19. Potassium is a silvery-white metal that is soft enough to be cut with a knife with little force. Potassium metal reacts rapidly with atmosphe ...

and

caesium Caesium (IUPAC spelling) (or cesium in American English) is a chemical element with the symbol Cs and atomic number 55. It is a soft, silvery-golden alkali metal with a melting point of , which makes it one of only five elemental metals that a ...

, rubidium has another hydrogen sulfate compound as well: Rb₃H(SO₄)₂.

References

{{rubidium compounds Rubidium compounds