Practice question

Given: What is the mass of 5 × 10²³ molecules of CH₄? (Molar mass = 16 g/mol, Avogadro number = 6 × 10²³) These values define the system as per NCERT data. Formula: Moles = 5 × 10²³ / 6 × 10²³ ≈ 0.8333 mol. This is the standard NCERT relation for this phenomenon. Substitution & Calculation: Mass = 0.8333 × 16 ≈ 13.33 g ≈ 13.3 g. 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.