Practice question

Given: In the reaction 4NH₃ + 5O₂ -> 4NO + 6H₂O, how many grams of O₂ are required to react with 17 g of NH₃? (Atomic masses: N = 14, H = 1, O = 16) These values define the system as per NCERT data. Formula: Molar mass of NH₃ = 17 g/mol. This is the standard NCERT relation for this phenomenon. Substitution & Calculation: Moles of NH₃ = 17 / 17 = 1 mol. 4 mol NH₃ require 5 mol O₂. Moles of O₂ = (5 / 4) × 1 = 1.25 mol. Mass = 1.25 × 32 = 40 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.