MHT CET202522 Apr 2025Evening ShiftChemistrySome Basic Concepts of ChemistryActual
What is the difference in molar masses of Undecane and Decane?
Options
- A140 ~g ~mol ⁻¹
- B70 ~g ~mol ⁻¹
- C24 ~g ~mol ⁻¹
- D14 ~g ~mol ⁻¹
Correct answer
D. 14 ~g ~mol ⁻¹
Step-by-step solution
Molar mass difference between undecane and decane Alkanes follow the general formula C_nH_ 2n+2 . Both undecane and decane belong to this homologous series where successive members differ by a CH₂ unit, which has a molar mass of 12 + (2 1) = 14 g mol ⁻¹ . The molar mass of CH₂ corresponds precisely to the mass difference between consecutive alkanes: C₁₁H₂₄ - C₁₀H₂₂ = CH₂ Therefore, the difference is 14 g mol ⁻¹ .