a mixture of methane and air is capable of being ignited only if the mole precen

Question

a mixture of methane and air is capable of being ignited only if the mole precent of methane is 5% or 15% . a mixture contaning 9.0 mole precent % of methane in air flowing at a rate 700. kg/h is to be diluted with pure air to reduce the methane concentration to the lower flammability limit . calculate the rquire flow rate of air in mol/h and the precent by mass of oxygen in the products gas. (note air may be taking to consist of 21 mole % O2 and 79 % N2 and to have an average molecular weight 29.0 .

Explanation / Answer

Start with a basis. 700 kg mixture. Mol. wt. mixture = (16 x 0.09) + (29 x 0.91) = 27.83 Rate of flow of mix = 700/27.83 = 25.15 moles/hr Methane = 2.264 moles/hr This is 9%. The minimum total flow rate required to reduce this to below 5% = 2.264 x 100/5 = 45.28 moles. Additional moles air needed = 45.28 - 25.15 = 20.13 moles /hr Mass of oxygen = 45.28 x 0.95 x 0.21 x 32 = 289.1 kg/hr

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.