Gas Laws in Stoichiometry Calculations?

A sample of O2 with a pressure of 1.50 atm and a volume of 265 mL is allowed to react with excess SO2 at 118 °C.

2 SO2 (g) + O2 (g) 2 SO3 (g)

Calculate the pressure of the SO3 (in atm) produced in the reaction if it is transferred to a 1.36-L flask and cooled to 30 °C.

I'm pretty sure some combination of the Ideal Gas Law and possibly Boyle's Law needs to be used. I'm just not sure how to get started.

Can someone walk me through the steps?

Thanks!

1 Answer

Relevance
  • 6 years ago
    Favorite Answer

    n = PV / RT = (1.50 atm) x (0.265 L) / ((0.08205746 L atm/K mol) x (118 + 273)K) = 0.01239 mol O2

    2 SO2 + O2 → 2 SO3

    (0.01239 mol O2) x (2 mol SO3 / 1 mol O2) = 0.02478 mol SO3

    P = nRT / V = (0.02478 mol) x (0.08205746 L atm/K mol) x (30 + 273)K / (1.36 L) = 0.453 atm SO3

    • Login to reply the answers
Still have questions? Get your answers by asking now.