13. i. For the reaction below, Kc 0.66 at a certain temperature. If a reaction f
ID: 698313 • Letter: 1
Question
13. i. For the reaction below, Kc 0.66 at a certain temperature. If a reaction flask contains 1.35 M NO2, 1.35 M NO, and 1.25 M O2, will the equilibrium concentration of NO2 be greater than, less than, or equal to 1.35 M? Provide work or an explanation to justify your answer. 2 NO2(g) 2 NO(g) + O2(g) ii. For the above exothermic equilibrium, how would the concentration of NO change if a. more O2 was added to the system? b. some NO2 was removed from the system? c. the reaction flask was cooled? d. the pressure was reduced by increasing the volume of the flask?Explanation / Answer
i) from equation:
Qc = [O2][NO]^2/[NO2]^2
= (1.25*1.35^2)/(1.35^2)
= 1.25
Qc > Kc. Backward reaction is favourable.
so that, concentration of No2 at equilibrium is greater than 1.35 .
ii)
a. equilibrium shifts towards left.backward reaction takes place.
b. equilibrium shifts towards left.backward reaction takes place.
c. equilibrium shifts towards right.forward reaction takes place.
d. so that, equilibrium shift towards more no of mol side.means right,forward reaction favourable.