Practice question

Given: What is the molality of a solution containing 5 g of urea (NH₂CONH₂) in 250 g of water? (Molar mass of urea = 60 g/mol) These values define the system as per NCERT data. Formula: Moles = 5 / 60 = 0.0833 mol. This is the standard NCERT relation for this phenomenon. Substitution & Calculation: Mass of solvent = 0.25 kg. Molality = 0.0833 / 0.25 ≈ 0.333 m. 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.