Answer: 47.2 g/mol
Explanation:
According to Dalton's law, the total pressure is the sum of individual pressures.
[tex]p_{total}=p_{gas}+p_{H_2O[/tex]
[tex]p_{total}[/tex] =753 torr
[tex]p_{H_2O[/tex] = 26.7 torr at [tex]27^0C[/tex]
[tex]p_{gas}=(753-26.7)torr=726.3 torr[/tex]
According to the ideal gas equation:'
[tex]PV=nRT[/tex]
P = Pressure of the gas = 726.3 torr = 0.95 atm (760torr=1atm)
V= Volume of the gas = 265 ml = 0.265 L (1L=1000ml0
T= Temperature of the gas = 27°C = 300 K (0°C = 273 K)
R= Gas constant = 0.0821 atmL/K mol
n= moles of gas=[tex]{\text {given mass}}{\text{molar mass}}[/tex]
[tex]n=\frac{PV}{RT}[/tex]
[tex]n=\frac{0.95\times 0.265}{0.0821\times 300K}=0.010moles[/tex]
moles of gas=[tex]\frac{\text {given mass}}{\text{molar mass}}[/tex]
[tex]0.010=\frac{0.472g}{\text{molar mass}}[/tex]
[tex]{\text {molar mass}}=47.2g/mol[/tex]
Thus the molar mass of the gas will be 47.2 g/mol
