The equilibrium constant for the reaction SO2(g) + NO2(g) ⇌ SO3(g) + NO(g) is Kc = 3.0. Find the amount of NO2 that must be added to 2.4 mol of SO2 in order to form 1.2 mol of SO3 at equilibrium.

Video transcript

Hello. And this problem we are told the reaction A plus B goes to C plus D where the equilibrium constant is equal to 0.60. To calculate the molds will be required to react with 1.8 moles of A to acquire 0. moles of C when the reaction reaches equilibrium. So we begin by creating an ice table. So first ride our reaction and then we have initial change in equilibrium. Initially, we have 1.8 moles of A. We're trying to determine our initial moles B and we have no sea and no D R changes minus X minus X. And then plus X plus X will combine the initial and the change to get our equilibrium. We're told that we have 0.9 moles of C at equilibrium. So that means X equals 0.90 at equilibrium, our equilibrium constant expression. Then we have the concentration of our products over that of our reactant. So plugging things in from the ice table, we have .90 times .90 All over 1.8 -1 which is again .90 and Y -X. So Y -0.90. And this is then equal to 0.60. Simplifying this, we then get 0.90 over Y minus 0.90, world 0.60. We will multiply both sides by Why -0.90. And then we'll simplify, Remove our 0.54 to the other side and then solve the why, Why works out to them 2.4 moles? This is our moles of B that we need them to react with 1.8 moles of a to produce 0.9 moles of c at equilibrium note here that we've made you some moles rather than polarity. And so we look at our concentrations that we would enter into our equilibrium constant expression, most similarity of our products over that of our reactant, we see then our units of volume cancel. So in this case, we can just make you some moles as we did in solving this problem. Thanks for watching. Hope this helps.