What is the {monoanion} for {conjugate base} of {citric acid}
What base is conjugate to citric acid?
What is the conjugate base of citric acid
SELECT DISTINCT ?u WHERE { ?u rdf:type ontology:monoanion . resource:citric_acid property:conjugate_base ?u }
select distinct ?obj where { ?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q159683> . ?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P4149> . ?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> ?obj . ?obj <http://www.wikidata.org/entity/P31> <http://wikidata.dbpedia.org/resource/Q55523986> } 
 select distinct ?obj where { wd:Q159683 wdt:P4149 ?obj . ?obj wdt:P31 wd:Q55523986 } 