Engineering Board Exam Reviewer · Chemistry · hard

What mass of air is needed to completely burn 1 kg of methane ( CH4 + 2 O2 CO2 + 2 H2O)? Air is 23.2% oxygen by mass. (Use H = 1, C = 12, N = 14, O = 16, Na = 23, S = 32, Cl = 35.5, Ca = 40)

Answer

A. 17.24 kg

O2 needed = 2(32)/16 = 4 kg per kg CH4. Air = 4/0.232 = 17.24 kg.

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