Rank the gas molecules CO2, C2H6, H2O, He, H2 in terms of increasing rate of effusion. 1. CO2, C2H6, H2O, He, H2 2. CO2, C2H6, H2O, H2, He 3. He, H2, H2O, C2H6, CO2 4. H2, He, H2O, C2H6, CO2 5. None of these

Ranking the gas molecules in terms of increasing rate of effusion  is given as CO2, C2H6, H2O, He, H2

Explanation:

The rate of effusion a gas is reciprocal to the square root of its molecular weight. The rate of effusion is to be arranged in the increasing rate of effusion. Arranging in terms of expanding rate of effusion, that is from heaviest to lightest molecule, (for example from smallest to highest effusion rate). The rate of effusion is higher for lighter molecule and also it effuses slowly.

                 Molar mass of CO2 = 44.01 g/mol

                 Molar mass of C2H6 = 30.07 g/mol

                 Molar mass of H2O = 18.01 g/mol

                 Molar mass of He = 4 g/mol

                 Molar mass of H2 = 2.01 g/mol

When the molecule has a high molecular weight, it slows the rate of effusion. Hence the gas molecules are arranged as CO2, C2H6, H2O, He, H2      

The answer is probably c. xylem