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NEETChemistrySome Basic Concepts of Chemistry

What is the mass of oxygen gas required for the complete combustion of 46 g of ethanol ( C₂H₅OH )? (Given atomic masses in amu: H = 1 , C = 12 , O = 16 )

Options

  1. A112 g
  2. B88 g
  3. C96 g
  4. D32 g

Correct answer

C. 96 g

Step-by-step solution

The balanced chemical equation for the complete combustion of ethanol is: C₂H₅OH + 3O₂ 2CO₂ + 3H₂O Molar mass of ethanol ( C₂H₅OH ) = (2 12) + (6 1) + 16 = 46 g/mol. Number of moles of ethanol = 46 46 = 1 mole. From the balanced equation, 1 mole of ethanol requires exactly 3 moles of O₂ for complete combustion. (The oxygen atom present in the ethanol molecule reduces the external O₂ requirement compared to a pure hydrocarbon like ethane). Molar mass of O₂ = 2 16 = 32 g/mol. Mass of O₂ required = 3 32 = 96 g. Forget

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