Question: why would a recrystallization need to be done
[{'answer': 'to purify chemicals', 'provenance': [{'wikipedia_id': '23681458', 'title': 'Recrystallization (chemistry)', 'start_paragraph_id': 1, 'start_character': 52, 'end_paragraph_id': 1, 'end_character': 71, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '23681458', 'title': 'Recrystallization (chemistry)', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 445, 'bleu_score': 0.970795021215021, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 5943562247438390125}, 'section': 'Section::::Abstract.'}]}]