Silver tetrafluoroborate Silver tetrafluoroborate Silver tetrafluoroborate is an inorganic compound with the chemical formula AgBF. It is a white solid that dissolves in polar organic solvents as well as water. In its solid state, the Ag centers are bound to fluoride. Silver tetrafluoroborate is prepared by the reaction between boron trifluoride and silver oxide in the presence of benzene. In the inorganic and organometallic chemistry laboratory, silver tetrafluoroborate, sometimes referred to "silver BF-4", is a useful reagent. In dichloromethane, silver tetrafluoroborate is a moderately strong oxidant. Similar to silver hexafluorophosphate, it is commonly used to replace halide anions or ligands with the
Britannia silver use by silversmiths from 1 June 1720, and thereafter Britannia silver has remained an optional standard for hallmarking in the United Kingdom and Ireland. Since the hallmarking changes of 1 January 1999, Britannia silver has been denoted by the millesimal fineness hallmark 958, with the symbol of Britannia being applied optionally. The silver bullion coins of the Royal Mint issued since 1997, known as "Britannias" for their reverse image, were minted in Britannia standard silver until 2012. Britannia silver should be distinguished from Britannia metal, a pewter-like alloy containing no silver. Britannia silver Britannia silver is an alloy of silver