What is the difference in molar mass of Undecane and Dodecane?

Step-by-step solution

Alkanes follow the general formula C_nH_ 2n+2 . For undecane ( n=11 ): C₁₁H₂₄ For dodecane ( n=12 ): C₁₂H₂₆ Using atomic masses C 12.01 g/mol and H 1.008 g/mol : Undecane molar mass: 11 12.01 + 24 1.008 = 156.302 g/mol Dodecane molar mass: 12 12.01 + 26 1.008 = 170.328 g/mol The difference is 170.328 - 156.302 = 14.026 g/mol , which rounds to 14 g/mol . Equivalently, consecutive alkanes differ by a CH₂ group with molar mass 12.01 + 2 1.008 = 14.026 g/mol . Correct option: D 14 g/mol