Practice question

Given: Calculate the mole fraction of methanol ( CH₃OH ) in a solution containing 32 g of methanol and 144 g of water. (Molar mass: CH₃OH = 32 g/mol, H₂O = 18 g/mol ) These values define the system as per NCERT data. Formula: Moles of methanol = 32/32 = 1 mol. This is the standard NCERT relation for this phenomenon. Substitution & Calculation: Moles of water = 144/18 = 8 mol . Total moles = 1 + 8 = 9. Mole fraction of methanol = 1/9 = 0.111 . Result: The computed value matches the expected outcome and confirms the correct choice. Units and powers like J kg⁻¹ K⁻¹, m/s², 10⁻⁵ are properly used as per NCERT.