3.9 moles of NO and 0.88 moles of CO2 are allowed to react as
NO + CO2 <--> NO2 + CO
At equilibrium 0.11 moles of CO2 was present. Kc for the reaction is _____
0.27
1.7
3.14
6.03
Don't you need to know how many liters, to figure Kc don't you have to change everything to M, so don't you need liters, or do you just assume 1.0 L?
Assume any value for volume? 1.0 L is the easy way go go.
Still confused, I have two concentrations for CO2 and none for NO2. If I change everything I have to M, how can I sub into the Kc formula without knowing the conc. of NO2 or haveing Kc?
NO + CO2 ==> NO2 + CO
CO2 was 0.88 to begin.
It was 0.11 at the end. So how much was used? That must be 0.88 - 0.11 = 0.77
Since all of the coefficients in the balanced equation are 1, then you must have used 0.77 of NO and must have formed 0.77 NO2 and 0.77 CO.
Just another ICE CHART.
Substitute the new values into the Kc expression and solve for Kc.
You are correct that in order to calculate the equilibrium constant (Kc) for a reaction, we usually need to know the initial concentrations of the reactants and products, as well as the equilibrium concentrations. Additionally, the units of concentration should be in molarity (M).
In this case, you mentioned the number of moles of each species at the beginning and at equilibrium, but we don't have the volume, so we cannot directly calculate the concentrations in M.
However, we can make an assumption that the volume is constant and we can treat it as 1.0 L. By assuming a volume of 1.0 L, we can directly use the moles to calculate the concentrations in M.
To determine the concentrations of the reactants and products, we divide the number of moles by the assumed volume (1.0 L). So, for the initial concentrations, we have:
[NO] = 3.9 moles / 1.0 L = 3.9 M
[CO2] = 0.88 moles / 1.0 L = 0.88 M
At equilibrium, you mentioned that 0.11 moles of CO2 is present. So, the equilibrium concentration of CO2 will be:
[CO2] = 0.11 moles / 1.0 L = 0.11 M
Now that we have the concentrations, we can use them to calculate the equilibrium constant (Kc) for the reaction using the formula:
Kc = ([NO2] * [CO]) / ([NO] * [CO2])
However, we don't have the values for [NO2] and [CO]. Without knowing these concentrations, we cannot calculate the exact value of Kc. Therefore, we cannot determine which option among 0.27, 1.7, 3.14, or 6.03 is the correct value of Kc.
In order to find the exact value of Kc, we would need additional information or data about the concentrations of the other species at equilibrium.