chemistry

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a 256 mL sample of an unknown gas was collected over water at 23 degrre celsius and 750 mmHg. the gas has a mass of 0.80 grams. what is the molar mass of the gas? (the vapor pressure of water at 23 degree celsius is 21.0 mmHg)

  • chemistry -

    Use PV = nRT and solve for n = number of mols. Then n = grams/molar mass and solve for molar mass.
    In the gas equation, for pressure substitute for P = (750-21/760)
    Don't forget T must be in kelvin. Volume must be entered in L.

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