Đốt cháy hết 19,5g kim loại kẽm Zn trong không khí thu được 24,3g kẽm oxit ZnO. Biết rằng kẽm cháy xảy ra phản ứng với khí oxi O2 trong không khí. a. Hãy lập phương trình hóa học của phản ứng trên. b. Cho biết tỉ lệ số nguyên tử Zn lần lượt với số phân tử của hai chất khác trong phản ứng. c. Viết công thức định luật bảo toàn khối lượng cho phản ứng trên. d. Tính khối lượng của khí oxi đã tham gia phản ứng. (O=16, Zn=65)

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