Sulfur hexafluoride gas is collected at 26.0 °c in an evacuated flask with a measured volume of 35.0 l. when all the gas has been collected, the pressure in the flask is measured to be 0.300 atm . calculate the mass and number of moles of sulfur hexafluoride gas that were collected. be sure your answer has the correct number of significant digits. mass: s mole

Moles of sulfur hexafluoride gas = 0.428 moles

Mass of sulfur hexafluoride gas = 62.5 g

Explanation:

Given that:

Pressure = 0.300 atm

Temperature = 26 °C

The conversion of T( °C) to T(K) is shown below:

T(K) = T( °C) + 273.15  

So,  

T = (26 + 273.15) K = 299.15 K  

Volume = 35.0 L

Using ideal gas equation as:

where,  

P is the pressure

V is the volume

n is the number of moles

T is the temperature  

R is Gas constant having value = 0.0821 L.atm/K.mol

Applying the equation as:

0.300 atm × 35.0 L = n × 0.0821 L.atm/K.mol × 299.15 K  

⇒n = 0.4275 moles

Moles of sulfur hexafluoride gas = 0.428 moles

Molar mass of sulfur hexafluoride gas = 146.06 g/mol

The formula for the calculation of moles is shown below:

Thus,

Mass of sulfur hexafluoride gas = 62.5 g