Chlorine pentafluoride gas is collected at -14.0 degrees Celcius in an evacuated flask with a measured volume of 30.0L When all the gas has been collected, the pressure in the flask is measured to be 0.260atm.
Calculate the mass and number of moles of chlorine pentafluoride gas that were collected. Round your answer to 3 significant digits.
To calculate the mass and number of moles of chlorine pentafluoride gas collected, we can use the Ideal Gas Law equation:
PV = nRT
Where:
P = pressure in atm
V = volume in liters
n = number of moles
R = ideal gas constant (0.0821 L·atm/(mol·K))
T = temperature in Kelvin
First, let's convert the temperature from Celsius to Kelvin:
T(K) = T(°C) + 273.15
T(K) = -14.0 °C + 273.15
T(K) = 259.15 K
Now, we can rearrange the Ideal Gas Law equation to solve for moles:
n = PV / RT
n = (0.260 atm) * (30.0 L) / (0.0821 L·atm/(mol·K) * 259.15 K)
n ≈ (7.8 mol·atm) / (21.285 mol·K)
n ≈ 0.366 moles
To calculate the mass, we need to know the molar mass of chlorine pentafluoride (ClF5). The molar mass can be calculated by adding the atomic masses of each element (1 Cl + 5 F):
Molar mass of ClF5 = (1 * Atomic mass of Cl) + (5 * Atomic mass of F)
= (1 * 35.453 g/mol) + (5 * 18.998 g/mol)
= 35.453 g/mol + 94.990 g/mol
= 130.443 g/mol
Now, we can calculate the mass:
Mass = n * Molar mass
Mass = 0.366 moles * 130.443 g/mol
Mass ≈ 47.669 g
Therefore, the mass of chlorine pentafluoride gas collected is approximately 47.669 grams and the number of moles is approximately 0.366 moles.
To calculate the mass and number of moles of chlorine pentafluoride gas collected, we can use the ideal gas law equation:
PV = nRT
Where:
P = pressure (in atm)
V = volume (in L)
n = number of moles
R = ideal gas constant (0.0821 L·atm/(mol·K))
T = temperature (in Kelvin)
First, we need to convert the temperature from Celsius to Kelvin:
T(K) = T(°C) + 273.15
T(K) = -14.0°C + 273.15 = 259.15 K
Now let's rearrange the ideal gas law equation to solve for the number of moles (n):
n = PV / RT
n = (0.260 atm) * (30.0 L) / (0.0821 L·atm/(mol·K)) * (259.15 K)
n = 3.0 mol (rounded to 3 significant digits)
To calculate the mass of chlorine pentafluoride gas, we need to know its molar mass. The molar mass of chlorine pentafluoride is the sum of the atomic masses of chlorine (Cl) and fluorine (F):
Molar mass = (1 mole Cl) + (5 moles F)
Molar mass = 35.45 g/mol + (5 * 18.99 g/mol) = 130.4 g/mol (rounded to 3 significant digits)
Mass = number of moles * molar mass
Mass = 3.0 mol * 130.4 g/mol = 391.2 g (rounded to 3 significant digits)
Therefore, the mass and number of moles of chlorine pentafluoride gas collected are approximately 391.2 grams and 3.0 moles, respectively.
Use PV = nRT.
You have a P, a V, you know R, and you have T (remember to convert to K). Solve for n = number of moles, then mass = moles x molar mass.