Câu 5. Đốt cháy 18,6g Photpho trong không khí tạo thành điphotpho pentaoxit (P2O5). a. Viết phương trình hóa học. b. Tính thể tích khí oxi cần dùng ở (đktc)? c. Tính thể tích không khí, biết thể tích khí oxi chiếm 20% thể tích không khí? d. Tính khối lượng chất tạo thành? (Cho: O = 16, P = 31, Cl = 35.5, K = 39)

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