Consider the following equilibrium: 742. °C. Answer the following questions abou
ID: 103596 • Letter: C
Question
Consider the following equilibrium: 742. °C. Answer the following questions about this system: o rise O fall Under these conditions, will the pressure of NO tend to rise or fall2 Is it possible to reverse this tendency by adding Cl2? In other words, if you said the pressure of NO will tend to rise, can that be changed to a tendency to fall by adding Cl? Similarly, if you said the pressure of NO will tend to fall, can that be changed to a tendency to rise by adding Cl2? yes If you said the tendency can be reversed in the second question, calculate the minimum pressure of Cl2 needed to reverse it. Round your answer to 2 significant digits. amExplanation / Answer
a.
since no Cl2 is present, the reaction, NOCl, must proceed forward to form some Cl2
it will rise, NO as well
b.
yes we can, via addition of Cl2 in order to favour Q = K
c.
from dG
dG = -RT*ln(K)
K = exp(-DG/(RT)) = exp(-41000/(8.314*298)) = 6.5027*10^-8
now...
K = [NO]^2[Cl2]/[NOCl]^2
6.5027*10^-8 = (1.91^2) * P-Cl2 /(3.05^2)
PCl2 = (6.5027*10^-8)/ (1.91^2)*(3.05^2)
P-Cl2 = 1.658*10^-7 atm required