Trong phòng thí nghiệm, người ta điều chế oxit sắt từ bằng cách dùng Oxi oxi hoá Sắt ở nhiệt độ cao. a) Tính thành phần % theo khối lượng của nguyên tố Sắt có trong oxit sắt từ? b) Tính số gam khí Oxi cần dùng để điều chế được 2,32g oxit sắt từ? c) Để điều chế được lượng Oxi nói trên cần phân hủy bao nhiêu gam KMnO4 ( coi như không có sự hao hụt trong quá trình điều chế) ? giúp mình vs ạ mình đang cần gấp. vote cho bạn có ctlhn nhé! :)

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