text: 1. Work out the moles of pure Mo.\n2. Multiply by 3 to get the moles of hydrogen.\n3. Use V = nRT/p to calculate the volume of hydrogen.\n4. Going back to the moles of Mo, multiply by 7/2 to get the moles of oxygen, and do a similar calculation to get the volume of pure oxygen.\n5. Multiply the volume of oxygen by 100/21 to get the volume of air.