Question

If it takes 4 seconds for hydrogen to diffuse from 1 and of a gas jar to another, how long will it take oxygen to diffuse through the same distance

Answer 1

Rate of effusion $=$ $Amount of gas \over time$

Combine with Grahams law;

$Rate of effusion of hydrogen\over Rate of effusion of Oxygen$ $=$ $\sqrt MO \over \sqrt MH$

To get

${Amount of H transferred \over time of H} \over{Amount of O transfared\over time of O}$ $=$ $\sqrt MO \over \sqrt MH$

$\therefore$ $Time of H\over Time of 0$ $=$ $\sqrt MO\over \sqrt MH$ $=$ $\sqrt MO\over \sqrt MH$

$Time of O\over 4s$ $=$ $\sqrt 32g/mol \over 2mol/L$ $=$ $\sqrt 16 \over \sqrt 1$

$Time of O \over 4s$ $=$ $4\over 1$

$=4*4=16$

Oxygen takes $16$ seconds to travel through the same distance.