You probably have noticed that ball

You probably have noticed that balloons inflated with
helium gas rise in the air the first day during a party but they
fall down the next day and act like ordinary balloons filled with
air. This is because the helium in the balloon slowly leaks out
through the wall while air leaks in by diffusion.
Consider a balloon that is made of 0.1-mm-thick soft rubber
and has a diameter of 15 cm when inflated. The pressure and
temperature inside the balloon are initially 110 kPa and 25°C.
The permeability of rubber to helium, oxygen, and nitrogen
at 25°C are 9.4  1013, 7.05  1013, and 2.6  1013
kmol/m · s · bar, respectively. Determine the initial rates of diffusion
of helium, oxygen, and nitrogen through the balloon
wall and the mass fraction of helium that escapes the balloon
during the first 5 h assuming the helium pressure inside the balloon
remains nearly constant. Assume air to be 21 percent oxygen
and 79 percent nitrogen by mole numbers and take the
room conditions to be 100 kPa and 25°C.

ผลลัพธ์ (อังกฤษ) 3:

You probably have noticed that balloons inflated with
helium gas rise in the air the first day during a party but they
fall. Down the next day and act like ordinary balloons filled with
air. This is because the helium in the balloon slowly leaks. Out
through the wall while air leaks in by diffusion.
Consider a balloon that is made of 0.1-mm-thick soft rubber
.And has a diameter of 15 cm when inflated. The pressure and
temperature inside the balloon are initially 110 kPa and 25 ° C.
The. Permeability of rubber to helium oxygen and,, nitrogen
at 25 ° C are 9.4  10  13 7.05 , 10  13 and 2.6,  10  13
KMOL / M experience, s Bachelor bar respectively. Determine, the initial rates of diffusion
of, helium oxygen and nitrogen, through the balloon
.Wall and the mass fraction of helium that escapes the balloon
during the first 5 h assuming the helium pressure inside. The balloon
remains nearly constant. Assume air to be 21 percent oxygen
and 79 percent nitrogen by mole numbers and take. The
room conditions to be 100 kPa and 25 ° C.