Diffusion, isn't this the formula I'm supposed to be using?

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    Diffusion Formula
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The discussion focuses on determining the molar mass of an unknown gas using the diffusion rates of nitrogen (N2) and the unknown gas. The formula for diffusion rates is correctly identified as the ratio of the rates being equal to the square root of the inverse ratio of their molar masses. Participants clarify that the faster gas is the lighter one, and they emphasize the importance of correctly applying the formula to obtain the molar mass. Despite confirming the formula's correctness, there is confusion regarding the final answer not matching available choices. The conversation underscores the need for clear application of the diffusion equation in solving for molar mass.
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A sample of an unknown gas takes 434 s to diffuse through a porous plug at a given temperature. At the same temperature, N2(g) takes 175 s to diffuse through the same plug. What is the molar mass of the unknown gas?

\frac {Rate_{A}}{Rate_{B}} = \sqrt {\frac {\mathcal{M}_{B}}{\mathcal{M}_{A}}}
 
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faster vs slower gas

which one is the faster gas? would the faster gas be the lighter or heavier gas?

try your equn this way

faster gas = sqrt (Mslower/Mfaster)
slower gas
 
Yes the formula is correct but how are you using it? That is show what your getting
 
ace123 said:
Yes the formula is correct but how are you using it? That is show what your getting
thanks, the answer doesn't even appear as one of the choices.
 
what did you get as an answer?
 
Last edited:
eli64 said:
what did you get as an answer?
i appreciate your help but i was really only concerned about the equation, thanks.
 

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