Question: what gas is given off by concentrated hydrochloric acid
[{'answer': 'hydrogen chloride', 'provenance': [{'wikipedia_id': '210755', 'title': 'Hydrogen chloride', 'start_paragraph_id': 1, 'start_character': 13, 'end_paragraph_id': 1, 'end_character': 30, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '210755', 'title': 'Hydrogen chloride', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 409, 'bleu_score': 0.8764938682572601, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 4256398539520608995}, 'section': 'Section::::Abstract.'}]}]