Rubidium carbonate

Rubidium carbonate, Rb2CO3, is a convenient compound of rubidium; it is stable, not particularly reactive, and readily soluble in water, and is the form in which rubidium is usually sold.

Rubidium carbonate
IUPAC name
Rubidium carbonate
3D model (JSmol)
ECHA InfoCard 100.008.666
RTECS number
  • FG0650000
Molar mass 230.945 g/mol
Appearance White powder,
very hygroscopic
Melting point 837 °C (1,539 °F; 1,110 K)[1]
Boiling point 900 °C (1,650 °F; 1,170 K) (decomposes)
Very soluble
−75.4·10−6 cm3/mol
Main hazards Irritant
Flash point Non-flammable
Related compounds
Other cations
Lithium carbonate
Sodium carbonate
Potassium carbonate
Caesium carbonate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).


It can be prepared by adding ammonium carbonate to rubidium hydroxide.[2]


It is used in some kinds of glass-making by enhancing stability and durability as well as reducing its conductivity. It is also used as a part of a catalyst for preparing short-chain alcohols from feed gas.[3]


  1. ^ Pradyot Patnaik. Handbook of Inorganic Chemicals. McGraw-Hill, 2002, ISBN 0-07-049439-8
  2. ^ Chisholm, Hugh, ed. (1911). "Rubidium" . Encyclopædia Britannica. 23 (11th ed.). Cambridge University Press. p. 809.
  3. ^ Canada Patents
Caesium carbonate

Caesium carbonate or cesium carbonate is a white crystalline solid compound. Caesium carbonate has a high solubility in polar solvents such as water, alcohol and DMF. Its solubility is higher in organic solvents compared to other carbonates like potassium and sodium carbonates, although it remains quite insoluble in other organic solvents such as toluene, p-xylene, and chlorobenzene. This compound is used in organic synthesis as a base. It also appears to have applications in energy conversion.

Glossary of chemical formulas

This is a list of common chemical compounds with chemical formulas and CAS numbers, indexed by formula. This complements alternative listing at inorganic compounds by element. There is no complete list of chemical compounds since by nature the list would be infinite.

Note: There are elements for which spellings may differ, such as aluminum/ aluminium, sulfur/ sulphur, and caesium/ cesium.

Lithium carbonate

Lithium carbonate is an inorganic compound, the lithium salt of carbonate with the formula Li2CO3. This white salt is widely used in the processing of metal oxides and treatment of mood disorders.

For the treatment of bipolar disorder, it is on the World Health Organization's List of Essential Medicines, the most important medications needed in a basic health system.


In chemistry, peroxydicarbonate (sometimes peroxodicarbonate) is a divalent anion with formula C2O2−6. It is one of the oxocarbon anions, which consist solely of carbon and oxygen. Its molecular structure can be viewed as two carbonate anions joined so as to form a peroxide bridge –O–O–.

The anion is formed, together with peroxocarbonate CO2−4, at the negative electrode during electrolysis of molten lithium carbonate. The anion can also be obtained by electrolysis of a saturated solution of rubidium carbonate in water.Potassium peroxydicarbonate K2C2O6 was obtained by Constam and von Hansen in 1895; its crystal structure was determined only in 2002. It too can be obtained by electrolysis of a saturated potassium carbonate solution at −20 °C. It is a light blue crystalline solid that decomposes at 141 °C, releasing oxygen and carbon dioxide, and decomposes slowly at lower temperatures.Rubidium peroxodicarbonate is a light blue crystalline solid that decomposes at 424 K (151 °C). Its structure was published in 2003. In both salts, each of the two carbonate units is planar. In the rubidium salt the whole molecule is planar, whereas in the potassium salt the two units lie on different and nearly perpendicular planes, both of which contain the O–O bond.

Potassium carbonate

Potassium carbonate is the inorganic compound with the formula K2CO3. It is a white salt, which is soluble in water. It is deliquescent, often appearing a damp or wet solid. Potassium carbonate is mainly used in the production of soap and glass.


Rubidium is a chemical element with the symbol Rb and atomic number 37. Rubidium is a very soft, silvery-white metal in the alkali metal group. Rubidium metal shares similarities to potassium metal and caesium metal in physical appearance, softness and conductivity. Rubidium cannot be stored under atmospheric oxygen, as a highly exothermic reaction will ensue, sometimes even resulting in the metal catching fire.Rubidium is the first alkali metal in the group to have a density higher than water, so it sinks, unlike the metals above it in the group. Rubidium has a standard atomic weight of 85.4678. On Earth, natural rubidium comprises two isotopes: 72% is a stable isotope 85Rb, and 28% is slightly radioactive 87Rb, with a half-life of 49 billion years—more than three times longer than the estimated age of the universe.

German chemists Robert Bunsen and Gustav Kirchhoff discovered rubidium in 1861 by the newly developed technique, flame spectroscopy. The name comes from the Latin word rubidus, meaning deep red, the color of its emission spectrum. Rubidium's compounds have various chemical and electronic applications. Rubidium metal is easily vaporized and has a convenient spectral absorption range, making it a frequent target for laser manipulation of atoms. Rubidium is not a known nutrient for any living organisms. However, rubidium ions have the same charge as potassium ions and are actively taken up and treated by animal cells in similar ways.

Rubidium bromide

Rubidium bromide is the bromide of rubidium. It has a NaCl crystal structure, with a lattice constant of 685 picometres.There are several methods for synthesising rubidium bromide. One involves reacting rubidium hydroxide with hydrobromic acid:

RbOH + HBr → RbBr + H2OAnother method is to neutralize rubidium carbonate with hydrobromic acid:

Rb2CO3 + 2HBr → 2RbBr + H2O + CO2Rubidium metal would react directly with bromine to form RbBr, but this is not a sensible production method, since rubidium metal is substantially more expensive than the carbonate or hydroxide; moreover, the reaction would be explosive.

Rubidium fluoride

Rubidium fluoride (RbF) is the fluoride salt of rubidium. It is a cubic crystal with rock-salt structure.

There are several methods for synthesising rubidium fluoride. One involves reacting rubidium hydroxide with hydrofluoric acid:

RbOH + HF → RbF + H2OAnother method is to neutralize rubidium carbonate with hydrofluoric acid:

Rb2CO3 + 2HF → 2RbF + H2O + CO2Another possible method is to react rubidium hydroxide with ammonium fluoride:

RbOH + NH4F → RbF + H2O + NH3The least used method due to expense of rubidium metal is to react it directly with fluorine gas, as rubidium reacts violently with halogens:

2Rb + F2 → 2RbF

Sodium carbonate

Sodium carbonate, Na2CO3, (also known as washing soda, soda ash and soda crystals) is the inorganic compound with the formula Na2CO3 and its various hydrates. All forms are white, water-soluble salts. All forms have a strongly alkaline taste and give moderately alkaline solutions in water. Historically it was extracted from the ashes of plants growing in sodium-rich soils. Because the ashes of these sodium-rich plants were noticeably different from ashes of wood (once used to produce potash), sodium carbonate became known as "soda ash". It is produced in large quantities from sodium chloride and limestone by the Solvay process.

Rubidium compounds


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