Suppose a 250. mL flask is filled with 0.80 mol of Cl2 and 1.8 mol of HCl. The following reaction becomes possible:
H2 (g)+Cl2 (g)-> 2HCl(g)
The equilibrium constant K for this reaction is 4.40 at the temperature of the flask.
Calculate the equilibrium molarity of H2
Round your answer to two decimal places.
The key to solving an equilibrium composition problem is the connection between the equilibrium molarities of each reactant and the equilibrium constant
You can use this equation to calculate K from the equilibrium molarities. But if you know K instead, you can use the equation "backwards" to calculate the equilibrium molarities.:
Next, substitute the expressions in the last row of the reaction table for the molarities in the equilibrium constant expression:
Although the quadratic formula gives you two values for x , only one is physically reasonable. Which one? Look back at the equilibrium molarities in the equilibrium table. None of them can be negative -- a negative molarity makes no physical sense.
Now that you know x go back to the last row of the reaction table and use it to calculate