Question

Calculate the molar mass of a vapor that has a density of 7.125 g/L at 13 ∘C and 741 torr .

Answer 1

Answer:

Molar Mass = 171.6 g/mol

Explanation:

Here we can use the equation PV = nRT, where n could stand for m / M, considering M = Molar Mass. Now we can rearrange this equation to isolate M, as we have to determine the " molar mass " of this vapor,

PV = ( m / M )RT,

density = mass / volume = PM / RT -

M = dRT / P

First convert celcius to kelvins and torr to " standard atmosphere " before plugging in the known values,

13 C = 286 K,

741 torr = 0.975 atm -

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M = (7.125)(0.0821) (286) / 0.975

M = 171.6 g /mol