Van’t Hoff equation and equilibrium concentration

Chemistry and homework help forum.

Organic Chemistry, Analytical Chemistry, Biochemistry, Physical Chemistry, Computational Chemistry, Theoretical Chemistry, High School Chemistry, Colledge Chemistry and University Chemistry Forum.

Share your chemistry ideas, discuss chemical problems, ask for help with scientific chemistry questions, inspire others by your chemistry vision!

Please feel free to start a scientific chemistry discussion here!

Discuss chemistry homework problems with experts!

Ask for help with chemical questions and help others with your chemistry knowledge!

Moderators: Xen, expert, ChenBeier

Post Reply
pliz89
Newbie
Newbie
Posts: 1
Joined: Sun Oct 08, 2017 4:42 pm

Van’t Hoff equation and equilibrium concentration

Post by pliz89 »

Hello,

I got this assignment.

Normal air (0.78% N2, 0.21% O2) is held at 2000K long enough to reach chemical
equilibrium with NO and NO2. Assume that the only reactions involving NO and NO2 are:
1) N2 + O2 - 2NO
2) NO + 0.5O2 - NO2

The equilibrium constants obtained at 300K for the formation of NO and NO2 are:

for 1) Keq:7 x 10^-31
for 2) Keq: 1.4 x 10^6

The standard heats of formation at 25ºC are:
HfºN2 = 0, HfºO2 = 0, HfºNO = 90.25 kJ/mol, HfºNO2 =33.2 kJ/mol

Please, could you help me about:

point.a) Using Van’t Hoff equation, Calculate the concentrations of all components when equilibrium is reached at 2000K

point.b) Plot the calculated equilibrium concentration of NO at two different oxygen contents of the reacting gas. Case 1 :78% nitrogen, 21% oxygen; and case 2: 78% nitrogen, 4% oxygen in a temperature range between 300 and 4000K

Thank you
Post Reply