Câu 1:Phân tử một hợp chất có công thức tổng quát là Y2O.Biết rằng phân tử của hợp chất này nhẹ hơn phân tử khí clo là 9đvC. a/Tính phân tử khối của hợp chất? b/Tính nguyên tử khối, cho biết tên, ký hiệu hóa học của Y. Câu 2:Phân tử một hợp chất có công thức tổng quát là Y2O.Biết rằng phân tử của hợp chất này nặng hơn phân tử khí oxi là 62đvC. a/Tính phân tử khối của hợp chất? b/Tính nguyên tử khối, cho biết tên, ký hiệu hóa học của Y. Từ đó suy ra CTHH của hợp chất. Câu 3:Phân tử một hợp chất gồm nguyên tử của nguyên tố Y liên kết với 2 nguyên tử oxi.Phân tử của hợp chất này nặng gấp hai lần phân tử khí oxy a/Tính phân tử khối của hợp chất? b/Tính nguyên tử khối, cho biết tên, ký hiệu hóa học của Y? c/Cho 1đvC=0,16605 x 10 mũ âm 23 gam. Hãy tính khối lượng theo đơn vị gam của phân tử hợp chất trên

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