calculate the molar weight of Freon-II, of 8.29 liters of its vapor at 200 degrees celcius and 790 mm Hg has a mass of 30.5 g.?
A gas sealed vial originally at 0.6 atm and 300 K, was heated at 450 K. What other property of the gas has changed? What is the value of this property after heating?
For the freon see your other post. For this other problem the pressure has changed. p1/t1 = p1/t2
t1 and t2 must be in kelvin.
To find the molar weight of Freon-II, we can use the Ideal Gas Law equation:
PV = nRT
Where P is the pressure, V is the volume, n is the number of moles, R is the ideal gas constant, and T is the temperature in Kelvin.
First, let's convert the given values to the appropriate units:
Volume (V) = 8.29 liters
Temperature (T) = 200 degrees Celsius = 200 + 273.15 = 473.15 Kelvin
Next, we can rearrange the formula to solve for the number of moles (n):
n = PV / RT
Pressure (P) = 790 mm Hg (we need to convert this to atmospheres, as R is expressed in atm)
1 atmosphere = 760 mm Hg
P = 790 mm Hg / 760 mm Hg = 1.0395 atm
Ideal gas constant (R) = 0.0821 L·atm/(mol·K)
Now, let's substitute the values into the formula to solve for the number of moles (n):
n = (1.0395 atm) * (8.29 L) / (0.0821 L·atm/(mol·K)) * (473.15 K)
n = 0.100 mol
Finally, we can calculate the molar weight (molar mass) of Freon-II:
Molar weight = Mass / Moles
Mass = 30.5 g
Moles = 0.100 mol
Molar weight = 30.5 g / 0.100 mol
Molar weight = 305 g/mol
Therefore, the molar weight of Freon-II is 305 g/mol.