Practice question

Given: A solution is made by mixing 30 mL of methanol ( CH₃OH ) and 70 mL of water, with a total volume of 95 mL. What is the volume percentage of methanol? (Density of methanol = 0.792 g/mL) These values define the system as per NCERT data. Formula: Volume % = fracVolume of methanolTotal volume × 100. This is the standard NCERT relation for this phenomenon. Substitution & Calculation: Given volume of methanol = 30 mL, total volume = 95 mL. Volume % = 30/95 × 100 = 31.58% . 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.