The mass fraction of each product when acetylene is burned with 10 percent excess oxygen in a cutting torch is 0.5 for carbon dioxide, 0.25 for water, and 0.25 for excess oxygen. The mass of oxygen used per unit mass of acetylene burned is 40/338 g/g.
To determine the mass fraction of each product when acetylene (C₂H₂) is burned with 10 percent excess oxygen in a cutting torch, we need to consider the balanced chemical equation for the combustion reaction: 2 C₂H₂ + 5 O₂ → 4 CO₂ + 2 H₂O.
From this equation, we can see that for every 2 moles of acetylene burned, 5 moles of oxygen are consumed. Therefore, the mass fraction of carbon dioxide (CO₂) is 4/8 = 0.5, and the mass fraction of water (H₂O) is 2/8 = 0.25. The remaining mass fraction is the excess oxygen, which is 1 - 0.5 - 0.25 = 0.25.
To calculate the mass of oxygen used per unit mass of acetylene burned, we can use the molar mass of acetylene (26 g/mol), the molar mass of oxygen (32 g/mol), and the balanced equation. We know that for every 2 moles of acetylene burned, 5 moles of oxygen are consumed.
Therefore, the mass of oxygen used per mole of acetylene is (5 x 32 g) / (2 x 26 g) = 40/13 g/mol. This can be converted to the mass of oxygen used per unit mass of acetylene by dividing it by the molar mass of acetylene: (40/13 g/mol) / (26 g/mol) = 40/338 g/g.
--The given question is incomplete, the complete question is
"Acetylene (C₂H₂) is burned with 10 percent excess oxygen in a cutting torch. Determine the mass fraction of each of the products. Calculate the mass of oxygen used per unit mass of acetylene burned. mfo2- 11102 / 1n C₂H₂- kg 02 / kg C₂H₂."--