Question: which metal reacts with alkali to produce hydrogen
[{'answer': 'Sodium hydroxide', 'provenance': [{'wikipedia_id': '57877', 'title': 'Sodium hydroxide', 'start_paragraph_id': 0, 'start_character': 0, 'end_paragraph_id': 0, 'end_character': 16, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '57877', 'title': 'Sodium hydroxide', 'start_paragraph_id': 55, 'start_character': 0, 'end_paragraph_id': 55, 'end_character': 414, 'bleu_score': 0.9684940092844061, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 13061043523319740306}, 'section': 'Section::::Production.\n'}]}]