Answer to Question #142570 in General Chemistry for Nielle

Question

Consider two 1-L samples of gas: one is H2 and the other is O2. Both are at 1 atm and 25°C. How do the samples compare in terms of (a) mass, (b) density, (c) RMS, and (d) time for a given fraction of molecules to effuse?

Answer 1

a) using pv=nRT . We see that mass is directly proportional to molecular mass. So oxygen has a higher mass compared to hydrogen here

b) density increases as mass increases. So, oxygen has a higher density than hydrogen

c) root mean speed is inversely proportional to the molecular mass. So hydrogen has a higher RMS than oxygen here

d) rate of effusion of a gas is inversely proportional to the square root of their molecular weight . So the lighter the gas, the faster it effuses. So hydrogen effuses faster than oxygen