Properties of Gases: Vapor Pressure and Ideal Gas Law

a.) What was the pressure of the vapor in the flask in atm?

a.) 0.958 atm

b.) What was the temperature of the vapor in K? What was the volume of the flask in liters?

b.) The temperature of the vapor is approximately 372.95 K. The volume of the flask is approximately 0.2711 L.

c.) What was the mass of the condensed vapor that was present in the flask?

c.) The mass of the condensed vapor in the flask is approximately 0.614 g.

d.) How many moles of condensed vapor were present?

d.) The number of moles of condensed vapor present is approximately 0.0107 moles.

e.) What is the mass of one mole of vapor?

e.) The mass of one mole of vapor is approximately 57.34 g/mol.

Answer:

To solve this problem, we can use the ideal gas law, PV = nRT, where P is the pressure, V is the volume, n is the number of moles of gas, R is the ideal gas constant, and T is the temperature in Kelvin.

a.) To find the pressure of the vapor in the flask in atm, we need to convert the given pressure from mmHg to atm. We can use the conversion factor: 1 atm = 760 mmHg. So, the pressure of the vapor in the flask is 728 mmHg / 760 mmHg/atm = 0.958 atm.

b.) To find the temperature of the vapor in Kelvin, we can use the given temperature in degrees Celsius and convert it to Kelvin using the formula: T(K) = T(°C) + 273.15. So, the temperature of the vapor is 98.8°C + 273.15 = 372.95 K. To find the volume of the flask in liters, we can convert the given volume from milliliters to liters. We can use the conversion factor: 1 L = 1000 mL. So, the volume of the flask is 271.1 mL / 1000 mL/L = 0.2711 L.

c.) To find the mass of the condensed vapor in the flask, we can subtract the mass of the empty flask and stopper from the mass of the flask and condensed vapor. The mass of the condensed vapor is 53.870 g - 53.256 g = 0.614 g.

d.) To find the number of moles of condensed vapor present, we can use the ideal gas law. Rearranging the equation, we have n = PV / RT. Plugging in the values, we get n = (0.958 atm) * (0.2711 L) / [(0.0821 L·atm/mol·K) * (372.95 K)]. Solving this equation, we find that the number of moles of condensed vapor present is approximately 0.0107 moles.

e.) To find the mass of one mole of vapor, we can divide the mass of the condensed vapor by the number of moles. The mass of one mole of vapor is 0.614 g / 0.0107 moles = 57.34 g/mol.

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