Question

At a certain temperature, the equilibrium constant for the following chemical equation is 2.00. At this temperature, calculate the number of moles of NO2(g) that must be added to 2.64 mol of SO2(g) in order to form 1.10 mol of SO3(g) at equilibrium.

SO2(g) + NO2(g) <--->SO3(g) + NO(g)

Answer 1

Do a RICE table

R: SO2(g) + NO2(g) <--> SO3(g) + NO(g)
I: 2.64 z 0 0
C: -X - x +x +x
E: 2.64-x z-x x x

the equation tells you what x is
Since 1.10 mol of SO3(g) is at equilibrium x must be 1.10

Revised E:
2.64 - 1.10, z - 1.10, 1.10, 1.10

[1.10][1.10]
------------ = 2
[1.54][z-1.10]

Solve for z.