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Complete combustion of 2.9 ~g of an oxygen-containing organic compound yielded 6.6 ~g of CO ₂ and 2.7 ~g of H ₂ O . If the vapour density of the compound is 29 , the number of hydrogen atoms present in one molecule of the compound is _____.

Correct answer

6

Step-by-step solution

Moles of CO ₂ produced = 6.6 44 = 0.15 ~mol Moles of carbon in the compound = 0.15 ~mol Mass of carbon = 0.15 12 = 1.8 ~g Moles of H ₂ O produced = 2.7 18 = 0.15 ~mol Moles of hydrogen atoms = 2 0.15 = 0.30 ~mol Mass of hydrogen = 0.30 1 = 0.3 ~g Mass of oxygen in the compound = Total mass - (Mass of C + Mass of H) W_ O = 2.9 - (1.8 + 0.3) = 2.9 - 2.1 = 0.8 ~g Moles of oxygen atoms = 0.8 16 = 0.05 ~mol Molar ratio of C : H : O = 0.15 : 0.30 : 0.05 = 3 : 6 : 1 Empirical formula of the compound is C ₃ H ₆ O . Empiric

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