Answer: There are now 2.07 moles of gas in the flask.
Explanation:
[tex]PV=nRT[/tex]
P= Pressure of the gas = 697 mmHg = 0.92 atm (760 mmHg= 1 atm)
V= Volume of gas = volume of container = ?
n = number of moles = 1.9
T = Temperature of the gas = 21°C=(21+273)K= 294 K (0°C = 273 K)
R= Value of gas constant = 0.0821 Latm\K mol
[tex]V=\frac{nRT}{P}=\frac{1.9\times 0.0821 \times 294}{0.92}=49.8L[/tex]
When more gas is added to the flask. The new pressure is 775 mm Hg and the temperature is now 26 °C, but the volume remains same.Thus again using ideal gas equation to find number of moles.
[tex]PV=nRT[/tex]
P= Pressure of the gas = 775 mmHg = 1.02 atm (760 mmHg= 1 atm)
V= Volume of gas = volume of container = 49.8 L
n = number of moles = ?
T = Temperature of the gas = 26°C=(26+273)K= 299 K (0°C = 273 K)
R= Value of gas constant = 0.0821 Latm\K mol
[tex]n=\frac{PV}{RT}=\frac{1.02\times 49.8}{0.0821\times 299}=2.07moles[/tex]
Thus the now the container contains 2.07 moles.
