A sample of oxygen gas has a volume of 8.00 L at 20.0 ° C and 700. torr. How many moles does the sample contain?
To determine the number of moles in the oxygen gas sample, we can use the ideal gas law equation:
PV = nRT
Where:
P = pressure of the gas (in atm)
V = volume of the gas (in liters)
n = number of moles of gas
R = ideal gas constant (0.0821 L·atm/K·mol)
T = temperature of the gas (in Kelvin)
First, let's convert the given values to the appropriate units:
20.0 °C = 20.0 + 273.15 = 293.15 K (temperature in Kelvin)
700. torr = 700. / 760 atm (pressure in atm)
Now we can substitute the values into the ideal gas law equation and solve for n:
(700. / 760) atm * 8.00 L = n * (0.0821 L·atm/K·mol) * 293.15 K
Simplifying the equation:
n = ((700. / 760) * 8.00) / (0.0821 * 293.15)
n ≈ 0.309 moles
Therefore, the oxygen gas sample contains approximately 0.309 moles of gas.