About: http://webisa.webdatacommons.org/179070406

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	A halogen or a hydrogen halide, in particular chlorine or hydrogen chloride, is then added, with constant stirring, in at least a two-fold, preferably at least a five-fold, molar excess, based on the magnesium-containing compound.
http://www.w3.org/ns/prov#wasQuotedFrom	google.com