Cho 3,36 gam bột sắt để lâu ngoài không khí đã xảy ra phản ứng hóa hợp với oxi tạo thành oxit sắt từ (Fe3O4). Khối lượng oxit thu được và thể tích không khí cần dùng (biết thể tích oxi chiếm 21% thể tích không khí). Chú ý làm tròn đến 3 chữ số thập phân.Các chất khí ở đktc.(Fe = 56, O = 16). Hỏi mFe3O4 và Vkk =?

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