JEE Main202325 Jan 2023Evening ShiftChemistrySome Basic Concepts of ChemistryActual

Number of hydrogen atoms per molecule of a hydrocarbon A having 85 . 8 % carbon is (Given : Molar mass of A = 84 g mol - 1 )

Correct answer

Step-by-step solution

Using table of empirical formula for the compound: Element Percentage Mole ratio C 85 . 8 85 . 8 12 = 7 . 15 1 H 14 . 2 14 . 2 1 = 14 . 2 2 Thus, empirical formula is CH 2 , empirical molecular mass = 14 Thus, Molecular   Mass Empirical   Mass   =   n 14 × n = 84 n = 6 ∴ Molecular formula C 6 H 12

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