It requires 24 hours for a sample of helium gas to effuse through a porous membrane. how long will it take for the same amount of oxygen gas to effuse through the same membrane? assume both gases are at the same temperature. a. 12 hours b. 68 hours c. 48 hours d. 8.5 hours e. 32 hours

B. 68 hours

Explanation:

The effusion is the escape of gas molecules through a tiny hole. Graham's law of effusion states that the rate of effusion of a gas is inversely proportional to the square root of the mass of its particles. So, for gas A and B:

rate of A/ rate of B = (√MB)/(√MA)]

Where M is the molar mass. The rate is the amount divided by time. So, calling A of helium gas (MA = 4 g/mol), and B as oxygen gas (MB = 32 g/mol), the amounts as A and B, and the times tA and tB:

(A/tA)/(B/tB) = (√32)/(√4)

Because they have the same amount, A = B

tB/tA = 5.657/2

tB/24 = 2.828

tB = 68 hours

sorry i was late, but i don't know what assignment your talking about, i'm in flvs as well, im in earth space science. but u are behind pace bc every class should be in the 3's or 4'

the best answer is d because the strong cohesion is caused by the ability of water molecules to undergo hydrogen bonding.

a is incorrect because when water solidifies, it becomes   ice, which expands and occupies a bigger volume for the same mass of water in its liquid state.

b is incorrect because water has high surface tension. besides bonding to itself it hydrogen bonds to other molecules at the top decreasing possibility for breaking of attractive forces.

c is incorrect because the water molecule has oxygen which is highly electronegative and so pulls the electron pair towards itself creating a dipole moment, making the molecule polar.

e is incorrect because water has strong adhesion, ability to stick to other molecules such as glass because of this molecules having stronger hydrogen bonding than water.