After 4.00 mol of C2H4(g) and 2.50 mol of Br2 (g) are placed in a sealed 1.0L container, the reaction reaches equilibrium and is written following: C2H4(g) + Br2(g) -> C2H4Br2(g) ... Calculate the equilibrium concentrations of all three substances.
Wouldn't you need the Keq for this reaction?
It doesn't give me the Keq. The information in the question is the only information I am given.
You can't do it without Keq.
You must have a graph with the equilibrium concentration of something given.
This Q was given to me with C2H4 having an eq. concentration of 2.5 M.
To calculate the equilibrium concentrations of all three substances, we need to use the given information and apply the principles of the equilibrium constant (K) and stoichiometry.
Step 1: Write the balanced chemical equation, including the stoichiometric coefficients:
C2H4(g) + Br2(g) -> C2H4Br2(g)
Step 2: Establish the initial concentrations of each species:
Initial concentration of C2H4 (C2H4)i = 4.00 mol / 1.0 L = 4.00 M
Initial concentration of Br2 (Br2)i = 2.50 mol / 1.0 L = 2.50 M
Initial concentration of C2H4Br2 (C2H4Br2)i = 0 M (No initial amount given)
Step 3: Determine the change in concentration for each species at equilibrium:
Let the change in concentration of C2H4 be x mol/L.
Let the change in concentration of Br2 be x mol/L.
Let the change in concentration of C2H4Br2 be x mol/L.
After the reaction reaches equilibrium, the concentrations will be:
C2H4 concentration: (C2H4)i - x
Br2 concentration: (Br2)i - x
C2H4Br2 concentration: (C2H4Br2)i + x
Step 4: Write the equilibrium expression for the given reaction:
K = [(C2H4Br2) / (C2H4)(Br2)]
Step 5: Use the given values and the equation from step 4 to solve for x:
K = [(C2H4Br2) / (C2H4)(Br2)]
K = [(C2H4Br2)i + x / (C2H4)i - x) * ((Br2)i - x)
Since the initial concentration of C2H4Br2 is 0 M, we can simplify the equation:
K = [(C2H4Br2) / (C2H4)(Br2)]
K = x / ((4.00 M - x) * (2.50 M - x))
Step 6: Solve the equation for x by substituting the known values and solving the quadratic equation:
K = x / ((4.00 M - x) * (2.50 M - x))
Solve for x.
Step 7: Once you have determined the value of x, substitute it back into the equilibrium expressions to find the concentrations:
C2H4 concentration at equilibrium = (C2H4)i - x
Br2 concentration at equilibrium = (Br2)i - x
C2H4Br2 concentration at equilibrium = (C2H4Br2)i + x
Note: Make sure to check units and significant figures at each step to ensure accurate calculations.
This step-by-step process will guide you through the calculation of equilibrium concentrations of all three substances in the given reaction.