1. The problem statement, all variables and given/known data Fe2+and Cr2O72- react as follows: 6Fe2+ + Cr2O7 2− + 14H + >>> 6Fe3+ + 2Cr3+ + 7H2O. The equilibrium constant for the reaction is 1×10^57. Calculate the equilibrium concentrations of the iron and chromium species if 10 mL each of 0.02M K2Cr2O7 in 1.14M HCl and 0.12M FeSO4 in 1.14M HCl are reacted. 2. Relevant equations 3. The attempt at a solution https://physicsforums-bernhardtmediall.netdna-ssl.com/data/attachments/97/97696-2f7ec586395970f64d734682baf6f166.jpg [Broken] This is the solution provided . I still don't understand as Cr3+ is 0.02M in the equation as the question give is K2Cr2O7 is 0.02M > does it mean 0.02M of Cr2O72- ??? Same goes to iron .