Chemical Forums
Chemistry Forums for Students => High School Chemistry Forum => Topic started by: kjh on December 07, 2017, 08:42:47 PM
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Two formulae are given.
N2O5 ⇌ N2O3 + O2, K1 = 1/4
N2O3 ⇌ N2O + O2, K2 = 3
(The equilibrium constants are based on concentrations)
How does the concentration of O2 change if N2O3 is added after the equilibrium is reached?
I thought the concentration of O2 would decrease because the equilibrium constant of the reverse of the first reaction K-1 is 4, which is bigger than K2.
But if you add the reverse of the first reaction and the second reaction, O2 on both sides cancel out. Does that mean there's no change in concentration?
I am trying to use mass balance equations to find out the answer, but it seems very difficult.
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If you have an equilibrium between N2O5 and N2O3, and one between N2O3 and N2O, then you have an equilibrium between N2O5 and N2O. Write the equation for this equilibrium and an expression for the equilibrium constant. What is this equal to?
Now suppose you add N2O3, and some or all of it disproportionates to N2O5 and N2O, with no net change in the concentration of O2. What will happen to the concentrations of N2O5 and N2O (and in particular, to the ratio [N2O]/[N2O5])? Is this consistent with the equilibrium? What change, if any, is necessary to re-establish equilibrium?