Question
A syringe that is filled to a volume of 50.0 mL has a mass of 41.247 g when empty and a mass of 41.305 g when filled with an ideal gas. The atmospheric pressure as measured with a barometer, which is equal to the pressure of the gas in the syringe, is 761.5 mm Hg. The gas in the syringe is at thermal equilibrium with the air in the room which is at a temperature of 24.0 degree C. Convert the room temperature (and the temperature of the gas in the syringe) to K from degree C. Convert the atmospheric pressure (and the pressure of the gas in the syringe) to atm from mm Hg. Remember that 1 atm is defined as exactly 760 mm Hg. By using the ideal gas law [liquation (15-1)], the volume of the gas (L), the pressure (atm) and the temperature of the gas (K), calculate the number of moles n of gas in the syringe. Equation 15 - 1: pv = nRT Calculate the mass of the gas in the syringe by subtracting the empty mass of the syringe from the mass of the syringe containing the gas. Determine the molar mass of the gas by substituting the mass of the gas as determined in step 4 and the number of moles of the gas from step 3 into Equation (15-2). Equation 15 - 2 MM=M/n.
Explanation / Answer
1. To solve this problem you need to use the following equation:
K =
