Engineering Board Exam Reviewer · Chemistry · hard
A gas has a density of 1.25 g/L at STP (273 K, 1 atm). What is its molar mass? (R = 0.08206 L· atm/mol· K)
- 56.0 g/mol
- 28.0 g/mol
- 17.9 g/mol
- 30.8 g/mol
Answer
B. 28.0 g/mol
Solution
M = RT/P = 1.25(0.08206)(273)/1 = 28.0 g/mol (likely N2 or CO).
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