Question

Balance the following equations in acidic or basic solution as indicated.
Cr2O7^2- + Hg ��������������������������� Hg+ + Cr^3+ (basic solution)

I got 14H2O + 2Cr2O7^2- + 3Hg ��������������������������� 3Hg^2+ + 2Cr^3+ 28OH-

but an answer key has something else and I can't figure out how I���������������������������m wrong