1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Determining the quantity in moles of the gas that remains unreacted ?

  1. Mar 2, 2009 #1
    1. The problem statement, all variables and given/known data

    Consider the following reaction, which takes place in an autoclave at 250 degrees C and 800 atm.

    NH3(g) + 7/4 O2(g) --> NO2(g) + 3/2 H20(g)

    Into the reaction vessel has been placed 200 L of NH3(g) and 120 L of O2(g). The reaction is allowed to go to completion. Determine the quantity, in moles, of the gas that remains unreacted.

    2. Relevant equations

    3. The attempt at a solution

    I really don't know what to do, so I just tried this:
    The ratio of moles of O2 to NH3 is 7/4:1. Therefore the volume ratio is also 7/4:1. If you react 120 L of O2, then:
    120 x 4/7 = 68.6 L NH3

    200 L NH3 - 68.6 L NH3 = 131.4 L NH3 left unreacted

    Then I put it into n = PV/RT to convert to moles and I get 2448.2 mol NH3 left unreacted.

    IS THIS CORRECT??? Thanks
    Detailed explanations would be greatly appreciated.
  2. jcsd
  3. Mar 2, 2009 #2


    User Avatar

    Staff: Mentor

    Seems OK.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook