Passage III

Gas effusion occurs when a gas moves through a tiny opening into a region of lower pressure. The rate in milliliters per second (mL/sec) is measured using the apparatus in Figure 1.

A 25 mL gas sample in a syringe freely escapes into a flask. The molecular mass, in a.m.u. (atomic mass units), for seven gases and the time required to completely effuse are recorded in Table 1. The densities (mass/volume) in grams per liter (g/L) and average molecular speed (average distance traveled by a molecule per second) in meters per second (m/sec) are also given.

Figure 2 shows a graph of the effusion rate versus the molecular mass of the gases.

16. Toy balloons are made out of a rubber material which normally has many microscopic pores. Five identical balloons are filled to a volume of 1.0 L, with CO2, air, NH3, He, and H2, respectively. According to the data in Table 1, if these are kept under the same conditions, which balloon will deflate first?

Answer and Explanation

Your Answer is

Correct Answer is F

Explanation

As mentioned in the background introduction at the beginning, the efffusion time refers to the time it takes for 25mL of gas to seep out completely. The shorter the time, the faster the balloon will be out of gas. Check table 1 to know that the hydrogen (H2) efffusion time is the shortest.