In: Chemistry
For the reaction SO3(g) + NO(g) NO2(g) + SO2(g) Kc was found to be 0.500 at a certain temperature. A reaction mixture is prepared in which 0.130 mol NO2 and 0.130 mol of SO2 are placed in a 3.00 L vessel. After the system reaches equilibrium what will be the equilibrium concentrations of all four gases?
the reaction is SO3(g) + NO ----> NO2(g)+SO2(g)
Kc = [SO2] [NO2]/ [SO3]*[NO]=0.5
[SO3][NO2]/ ]SO2] [NO2] =1/0.5= 2
since the coefficients in the numerator and denominator are same. wther one takes moles or concentrations does not make any difference
Moles SO3 NO NO2 SO2
Iniritial 0 0 0.13 0.13
At eq. x x 0.13-x 0.13-x
x= moles of SO3 formed at equilibrium
Kc= 2= [SO3] [NO]/ [SO2][NO2] = x2/(0.13-x)2 =2
taking square root gives
x/(0.13-x)= sqrt(2)= 1.44
x= 1.44*(0.133-x)
2.44x= 1.44*0.133
x= 0.0785
At equilibfrium [SO3] =[NO] =0.0785/3 =0.026 [SO2] =(0.13-0.0.0785)/3=0.017167