MCAT practice questions

by goldstandard_mcat (Posted Mon Apr 02, 2018 4:56 am) Two identical evacuated flasks are filled with different gases to the same pressure and temperature. The first is filled with hydrogen and the second with propane. Compared with the first flask, the flask filled with propane weighs:A. 11 times more.B. 22 times more.C. the same.D. 44 times more.Correct answer: BRearranging the ideal gas equation, we get:n = PV/RT.Since P, V, and T are the same for both gas samples, n is also the same. However, propane has a molecular weight of 44, while H2 has a molecular weight of 2. Therefore, a molecule of propane weighs 22 times more than a molecule of hydrogen. Consequently, the sample of propane weighs 22 times more than the sample of hydrogen.(C) Gold Standard MCAT https://www.mcat-prep.com/mcat-practice-tests/
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