Final answer:
To calculate the mass of O₂ in the flask, convert pressure to atmospheres, temperature to Kelvin, and use the ideal gas law to find moles of O₂.
Step-by-step explanation:
The pressure of O₂ in a 15.0 L flask is 322 mm Hg at 44 °C. To find the mass of O₂ in the flask, we first convert pressure to atmospheres since the gas constant R is given in units of L·atm/mol·K. One atmosphere is equivalent to 760 mm Hg, so 322 mm Hg is 322/760 atm.
Next, we need to convert the temperature from °C to Kelvin, which is done by adding 273.15 to the Celsius temperature. Thus, the temperature is (44+273.15) K. We can then use the ideal gas law PV = nRT to solve for the number of moles (n) of O₂, (322 mm Hg / 760 mm Hg)×15 L = n×0.08206 L·atm/mol·K×(44°C + 273.15 K).
Once we have the moles of O₂, we can calculate the mass using the molar mass of O₂, which is approximately 32.00 g/mol. Thus, the mass is the product of the number of moles and the molar mass: n×32.00 g/mol = Mass of O₂.