Question

Biochemistry Question:
ATP hydrolysis

ATP + glucose --> glucose-6-phosphate + ADP
Delta Go' (-7.3 Kcal/mol)
37 degree celsius (310K)
ATP [5mM] Glucose [5mM]
[G6P]=[2mM] ADP [1mM]

Find Overall Delta G
DeltaG overall = DeltaGo'(Kcal/mol) +(0.00198 Kcal/mol*K)(310K)ln(Products(M)/reactants(M))

The answer should be -5.186 Kcal/mol..... But im not getting that answer. Instead Im getting -8.54 Kcal/mol. What am I doing wrong?