Engineering Board Exam Reviewer · Thermodynamics · medium
Air consists of approximately 79% N2 and 21% O2 by mole. What is its apparent molecular weight? (M N2 = 28, M O2 = 32)
- 30.00 kg/kmol
- 28.84 kg/kmol
- 31.16 kg/kmol
- 60.00 kg/kmol
Answer
B. 28.84 kg/kmol
Solution
M = yi Mi = 0.79(28) + 0.21(32) = 28.84 kg/kmol.
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