Question

From the following data, determine the molar mass of a gaseous sample.

Volume: 350 mL           Pressure: 756.8 Torr              t: 23.5 ^°C      w = 30 grams

Answer 1

use ideal gas equation for calculation of mole of gas

Ideal gas equation

PV = nRT             where, P = atm pressure= 756.8torr = 0.9957 atm,

V = volume in Liter = 350 ml = 0.350 L

n = number of mole = ?

R = 0.08205L atm mol^-1 K^-1 =Proportionality constant = gas constant,

T = Tempreture in K = 23.5⁰ = 273.15+ 23.5 = 296.55 K

we can write ideal gas equation

n = PV/RT

substitute the value

n = (0.99570.350)/(0.08205296.55) = 0.01432 mole

30 gm = 0.01432 mole then 1 mole = 130/0.01432 = 2094.97

molar masses of gaseous sample is 2094.97 gm/mol