Question

to provide an inert atmosphere to purge a reactor vessel, methane is burned in air to produce a mixture of CO₂ , H₂O , and N₂ . determine what mass ratio of air to methane should be fed to the burner to provide such a gaseous mixture. assume that air is 23% by mass O₂ and the remainder is N₂ .

Answer 1

To provide an inert atmosphere to purge a reactor vessel, the mass ratio of air to methane should be approximately 1.81. This is determined based on the balanced equation for the combustion of methane, which shows that for every 1 mole of methane, 2 moles of oxygen are needed.

Step-by-step explanation:

To provide an inert atmosphere to purge a reactor vessel, you need to burn methane in air to produce a mixture of CO₂, H₂O, and N₂. The mass ratio of air to methane can be determined based on the balanced equation for the combustion of methane:

CH₄ + 2O₂ → CO₂ + 2H₂O

From the equation, we can see that for every 1 mole of methane, we need 2 moles of oxygen. Since air is 23% oxygen and the remaining is nitrogen, we can calculate the mass ratio of air to methane:

1. Calculate the molar mass of air: (0.23 * 32g/mol) + (0.77 * 28g/mol) = 28.96 g/mol
2. Calculate the molar mass of methane: 12g/mol + 4 * 1g/mol = 16g/mol
3. Calculate the mass ratio: 28.96g/mol / 16g/mol = 1.81

Therefore, the mass ratio of air to methane should be approximately 1.81.