If 9.006 grams of a gas are enclosed in a 50.00 liter vessel at 273.15 K and 2.000 atmospheres of pressure, what is the molar mass of the gas? What gas is this?

Asked by Topperlearning User | 20th Apr, 2015, 11:38: AM

Expert Answer:

P = 2.000 atm

V = 50.00L

R = 0.0821 L atm mol-1 K-1

T = 273 K

We know,

begin mathsize 11px style straight n space equals space PV over RT
straight n space equals space fraction numerator left square bracket left parenthesis 2.000 space atm right parenthesis space left parenthesis 50.00 space straight L right parenthesis right square bracket over denominator left square bracket left parenthesis 0.0821 space straight L space atm space mol to the power of negative 1 end exponent space straight K to the power of negative 1 end exponent right parenthesis space left parenthesis 273 space straight K right parenthesis right square bracket end fraction
straight n space equals space 4.461 space mol
Molecular space weight space equals space fraction numerator Weight space over denominator Number space of space moles end fraction
Molecular space weight space equals space fraction numerator 9.006 over denominator 4.461 end fraction
Molecular space weight space equals space 2.019 space straight g space mol to the power of negative 1 end exponent end style

The answer (2.019 g mol-1) is approximately that of hydrogen gas, H2.

 

 

Answered by  | 20th Apr, 2015, 01:38: PM