Consider the following unbalanced redox reaction. Cr2O2?7(aq)+Cu(s)?Cr3+(aq)+Cu2+(aq)

A) Balance the equation:
?Cr2O2?7(aq)+?H+(aq)+?Cu(s)??Cr3+(aq)+?H2O(l)+?Cu2+(aq)
Give your answer as an ordered set of numbers ?, ?, ?, ... Use the least possible integers for the coefficients.
B) Determine the volume of a 0.900M K2Cr2O7 solution required to completely react with 5.35g of Cu.