Na2HPO4 x 2 H2O

[HISTORICAL — superseded by the #321 re-grade below: this record is a hydrate of CHEBI:91258, not an exact match to it] Imported from CultureMech pipeline, quality=DIRECT_MATCH

Promoted off the anhydrous term CHEBI:34683, which was absorbing five distinct Na2HPO4 hydrates, to the specific term CHEBI:91258 ('disodium hydrogenphosphate dihydrate') — MAPPING_SEMANTICS §3 step 1. cas_rn '7558-79-4' -> '10028-24-7', taken from ChEBI's own xref on the specific term; the previous value was shared across the family and did not denote this hydrate (#334).

identifier CHEBI:91258 -> kgmicrobe.compound:na2hpo4_x_2_h2o; mapping_quality EXACT_MATCH -> NARROW_MATCH. The record is a hydrate of CHEBI:91258 ('disodium hydrogenphosphate dihydrate') and was sharing that term's identifier — the identity collapse MAPPING_SEMANTICS §3 forbids, which made a distinct substance indistinguishable from its anhydrous parent downstream. ChEBI has no term for this hydrate and the record carries no verified CAS, so steps 1 and 2 are unavailable and step 3 applies.

molecular_formula 'HO4P.2Na' -> '2H2O.HO4P.2Na'. The recorded value described the anhydrous salt while the label names a hydrate, understating the mass by 18 g/mol per water. Corrected because adopted verbatim from the mapped term CHEBI:91258 ('disodium hydrogenphosphate dihydrate'), which is the specific hydrate and already carries the water.

mapping_quality NARROW_MATCH -> CLOSE_MATCH, predicate skos:narrowMatch -> skos:closeMatch. narrowMatch asserts this record is *narrower in meaning* than CHEBI:91258 ('disodium hydrogenphosphate dihydrate') — a subsumption ChEBI itself denies: it files hydrates under CHEBI:35505 'hydrate', never under the anhydrous compound, which is not an ancestor even transitively. A hydrate is a distinct substance containing the anhydrous form, not a specialization of it. closeMatch claims similarity without subsumption. The ontology_id and the record's own identifier are unchanged.