Question: is the quantity of a substance in a mixture per unit volume of the mixture
[{'answer': 'Amount of substance', 'provenance': [{'wikipedia_id': '759264', 'title': 'Amount of substance', 'start_paragraph_id': 0, 'start_character': 0, 'end_paragraph_id': 0, 'end_character': 19, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]