Hydrogen effuses four times more rapidly than volume of an unknown gas molar mass of unknown gas should be_______________? July 9, 2022March 17, 2019 by admin Hydrogen effuses four times more rapidly than volume of an unknown gas molar mass of unknown gas should be_______________? A. 16 gmol-1B. 32 gmol-1 C. 48 gmol-1 D. 64 gmol-1