Example:
It takes gas A 2.3 times as long to effuse through an orifice as the s
amount of nitrogen. What is the molar mass of gas ?

To find the molar mass of gas A, we can employ Graham’s Law of Effusion. According to the law, the rate of effusion of a gas is inversely proportional to the square root of its molar mass. Given that gas A takes 2.3 times longer than nitrogen (which has a known molar mass of approximately 28 g/mol), we can express the relationship as follows:

Squaring both sides yields , leading to . Voilà! The molar mass of gas A is about 5.29 g/mol!

Now, let’s think about how frequently gas effusion occurs in real life. For example, balloons filled with helium deflate faster than those filled with air because helium molecules are lighter and effuse more rapidly. This phenomenon explains why helium-filled balloons float but shrivel up quicker than their air-filled counterparts. Next time you see a floating balloon, remember that it’s all about the gas’s molar mass and effusion rates!

Also, sometimes the calculations can get a bit tricky, and common mistakes include neglecting to square both sides when dealing with rates of effusion, or mixing up the order of gases. To avoid that, it’s essential to keep track of which gas is being compared and to ensure that the relationship is correctly applied! Always double-check your work to catch any pesky mistakes!