H 2 O) can efficiently catalyze the addition of alcohols, substituted anilines and heterocyclic amines to phenylacetylene to afford substituted enol ethers and enamines. [83] Like other alkali metals, caesium has a great affinity for oxygen and is used as a "getter" in vacuum tubes. Sulfuric acid - diluted solution. [11][90] Radioactive isotopes of caesium in radiation devices were used in the medical field to treat certain types of cancer,[91] but emergence of better alternatives and the use of water-soluble caesium chloride in the sources, which could create wide-ranging contamination, gradually put some of these caesium sources out of use. After reduction of the hexachloroplatinate with hydrogen, caesium and rubidium were separated by the difference in solubility of their carbonates in alcohol. Cesium Hydroxide is used as electrolyte in alkaline batteries at subzero temperatures, color photography and as a catalyst in organic synthesis. Cesium hydroxide solution 50 wt. The first accurate caesium clock was built by Louis Essen in 1955 at the National Physical Laboratory in the UK. [11], The metal can also be isolated by electrolysis of fused caesium cyanide (CsCN). [76] Caesium clocks regulate the timing of cell phone networks and the Internet.[77]. [110], The median lethal dose (LD50) for caesium chloride in mice is 2.3 g per kilogram, which is comparable to the LD50 values of potassium chloride and sodium chloride. [68] In 1882, he produced caesium metal by electrolysing caesium cyanide, avoiding the problems with the chloride.[70]. It is also used in the catalytic conversion of sulfur dioxide into sulfur trioxide in the production of sulfuric acid.[11]. In the two-electrode vacuum tube converter, caesium neutralizes the space charge near the cathode and enhances the current flow. [80][81] Nevertheless, germanium, rubidium, selenium, silicon, tellurium, and several other elements can be substituted for caesium in photosensitive materials.[11]. The International System of Units (SI) defines the second as the duration of 9,192,631,770 cycles at the microwave frequency of the spectral line corresponding to the transition between two hyperfine energy levels of the ground state of caesium-133. It is used in photoelectric cells because caesium-based cathodes, such as the intermetallic compound K2CsSb, have a low threshold voltage for emission of electrons. [11], Roasting pollucite with calcium carbonate and calcium chloride yields insoluble calcium silicates and soluble caesium chloride. [95], Caesium-137 has been used in hydrologic studies analogous to those with tritium. [92][93] Caesium-137 has been employed in a variety of industrial measurement gauges, including moisture, density, levelling, and thickness gauges. Caesium hydroxide is a very strong base, and will rapidly corrode glass. Exceptionally pure and gas-free caesium can be produced by 390 °C (734 °F) thermal decomposition of caesium azide CsN3, which can be produced from aqueous caesium sulfate and barium azide. [11], Magnetohydrodynamic (MHD) power-generating systems were researched, but failed to gain widespread acceptance. The function of a drilling fluid is to lubricate drill bits, to bring rock cuttings to the surface, and to maintain pressure on the formation during drilling of the well. [69] The electrolysis of the aqueous solution of chloride with a mercury cathode produced a caesium amalgam which readily decomposed under the aqueous conditions. [73] Caesium formate brine can be blended with potassium and sodium formates to decrease the density of the fluids to that of water (1.0 g/cm3, or 8.3 pounds per gallon). Caesium-134, and to a lesser extent caesium-135, have also been used in hydrology to measure the caesium output by the nuclear power industry. Find another reaction. Cesium also plays a role in getting oil to run your car and power your home. [11] Caesium also was, and still is, used as a source of positive ions in secondary ion mass spectrometry (SIMS). [84] Other uses of the metal include high-energy lasers, vapour glow lamps, and vapour rectifiers. To supply the developing market, Cabot Corporation built a production plant in 1997 at the Tanco mine near Bernic Lake in Manitoba, with a capacity of 12,000 barrels (1,900 m3) per year of caesium formate solution. 2CsOH + H 2 SO 4 → Cs 2 SO 4 + 2H 2 O [ Check the balance ] Cesium hydroxide react with sulfuric acid to produce cesium sulfate and water. [11], The high density of the caesium formate brine (up to 2.3 g/cm3, or 19.2 pounds per gallon),[73] coupled with the relatively benign nature of most caesium compounds, reduces the requirement for toxic high-density suspended solids in the drilling fluid—a significant technological, engineering and environmental advantage. The largest present-day use of nonradioactive caesium is in caesium formate drilling fluids for the extractive oil industry. [121], It differs from this value in caesides, which contain the Cs. [111] The principal use of nonradioactive caesium is as caesium formate in petroleum drilling fluids because it is much less toxic than alternatives, though it is more costly. Potassium, rubidium, and caesium form insoluble salts with chloroplatinic acid, but these salts show a slight difference in solubility in hot water, and the less-soluble caesium and rubidium hexachloroplatinate ((Cs,Rb)2PtCl6) were obtained by fractional crystallization. This solution can be evaporated to produce caesium chloride or transformed into caesium alum or caesium carbonate. [85] This technology is used primarily in the isolation of viral particles, subcellular organelles and fractions, and nucleic acids from biological samples. [16], The isotopes 134 and 137 are present in the biosphere in small amounts from human activities, differing by location. [11], The high density of the caesium ion makes solutions of caesium chloride, caesium sulfate, and caesium trifluoroacetate (Cs(O2CCF3)) useful in molecular biology for density gradient ultracentrifugation. The high water solubility is a disadvantage which makes it incompatible with large pool irradiators for food and medical supplies. They have also been used to treat epilepsy. Completion fluids assist the emplacement of control hardware after drilling but prior to production by maintaining the pressure.