Consider the following reactions and their equilibrium constants at 303 K. PCl5(g) equilibrium reaction arrow 1/4 P4(g) + 5/2 Cl2(g); Kc = 1.18 ✕ 10−21 1/4 P4(g) + 3/2 Cl2(g) equilibrium reaction arrow PCl3(g); Kc = 2.28 ✕ 1026 Calculate Kc for PCl5(g) equilibrium reaction arrow PCl3(g) + Cl2(g) at the same temperature.

The value of for the net reaction is

Explanation:

The given chemical equations follows:

Equation 1:  

Equation 2:  

The net equation follows:

As, the net reaction is the result of the addition of two above equations. So, the equilibrium constant for the net reaction will be the multiplication of two above equations.

The value of equilibrium constant for net reaction is:

We are given:

Putting values in above equation, we get:

Hence, the value of for the net reaction is

first, consult an activity series chart to determine if al is more reactive than fe. it is, so it will replace the fe. now, one can continue with the problem.

next, make sure you have a correctly balanced equation.

3feo + 2al ==> 3fe + al2o3

now, determine which reactant (feo or al) is in limiting supply.

moles feo present = 125 g x 1 mole/71.8 g = 1.74 moles

moles al present = 25.0 g x 1 mole/26.98 g = 0.927 moles

since from the balanced equation, it take 3 mol feo for every 2 mol al, al will be limiting.

you can determine this simply by dividing moles of each by their coefficient in the balanced equation. for example: 1.74/3 = 0.58 and 0.927/2 = 0.464. al is less, so it is limiting.

finally, using the stoichiometry in the balanced eq. determine mass of fe that can be produced from 0.927 moles of al.

0.927 moles al x 3 moles fe/2 moles al x 55.8 g/mole = 77.6 g

put the answers   and i could answer.