The equilibrium constant for isomerization reaction is 
Further Explanation:
The standard Gibbs free energy change in a reaction  is the difference of sum of the standard free energies of formation of product molecules and sum of standard free energies of formation of reactant molecules at the standard conditions. The formula used to calculate the value of standard Gibbs free energy  change for a reaction
 is the difference of sum of the standard free energies of formation of product molecules and sum of standard free energies of formation of reactant molecules at the standard conditions. The formula used to calculate the value of standard Gibbs free energy  change for a reaction  is as follows:
 is as follows:

Here, n is the stoichiometric coefficients of products, and m are the stoichiometric coefficients of reactants in a balanced chemical equation.
The formula to determine the relationship between change in standard Gibbs free energy  and equilibrium constant
 and equilibrium constant  is given as follows:
 is given as follows:
 ......(1)
       ......(1)
Here,
 is the standard Gibbs free energy change.
 is the standard Gibbs free energy change.
 is the gas constant.
 is the gas constant.
 is the temperature in Kelvin.
 is the temperature in Kelvin.
 is the equilibrium constant.
 is the equilibrium constant.
The isomerization of glucose-1-phosphate to fructose-6-phosphate occurs in 2 steps:  
The reaction of step 1 is as follows: 

                                        ......(2)
 for equation (2) is
 for equation (2) is  
The reaction of step 2 is as follows: 

                                                    ......(3)
 for equation (3) is
 for equation (3) is  
Reverse the reaction of step 2.

                                                 ......(4)
 for equation (4) is
 for equation (4) is 
Add equation (1) and (3) to get the final equation.

To calculate  , add
, add  and
 and  as follows:
 as follows:  
 ......(5)
                       ......(5)
Substitute  for
 for  and
 and  for
 for  in equation (5).
 in equation (5).

For equilibrium constant (K), rearrange equation (1)
 ......(6)
    ......(6)
Substitute  for
 for  ,
, for R and
 for R and  for T in equation (6)
 for T in equation (6)

The equilibrium constant for the reaction is 9.615.
Learn more:
1. The change in standard gibbs free is for a reaction: brainly.com/question/10838453
2. Determination of the equilibrium constant for pure water: brainly.com/question/3467841
Answer details:
Grade: Senior Secondary School
Subject: Chemistry
Chapter: Chemical Equilibrium
Keywords: Standard Gibbs free energy, equilibrium, constant, glucose-1-phosphate and fructose-6-phosphate.