Posted by anita on Saturday, December 15, 2012 at 4:54am.
A latex balloon, wall thickness 3.091 x 104 m, contains helium at a concentration of 0.35 kg m3. Under these conditions the total surface area of the balloon is 0.57 m2. The diffusion coefficient of He in latex at room temperature is 4.9 x 109 m2s1. Calculate the rate of helium effusion (in g/hr) from the balloon.

chemistry  Shakti, Saturday, December 15, 2012 at 6:02am
maybe:
0.52*(4.9*10^9)*(concentration in mole/0.52)
then multiply solution (molar flow rate) with molar mass of helium.
solution should be effusion rate.
its just a suggestion, all other interested are invited to post their opinion/formula... 
chemistry  Ling, Saturday, December 15, 2012 at 6:22am
Could someone insert the data into the formula?

chemistry  Antonio, Saturday, December 15, 2012 at 6:22am
This is a question from the second midterm of 3.091x by edx. Stop cheating, it's silly and pointless.

chemistry  chelo, Saturday, December 15, 2012 at 8:10pm
what is the formula?

chemistry  Stud, Saturday, December 15, 2012 at 11:21pm
Fick’s Law
M= D•(Δρ/Δx)•A,
where
M = m/t = mass flux [kg/s],
D= 4.9•10 ⁻⁹ m ²/s is the diffusion coefficient (diffusivity) [m²/s],
Δρ/Δx is the gradient of density [kg/m⁴],
A is the area [m²].
M=  4.9•10⁻⁹•(0  0.35)/3.091•10⁻⁴)•0.88 =
4.9•10⁻⁹•0.35•0.88/3.091•10⁻⁴=
=4.88•10⁻⁶ kg/s= 17.58 g/hr