Balance this <span title="equation.........................................?">equation....................</span>

Question

Fe2+ + Cr2O72- = Fe3+ + Cr3+

Answer 1

This is a redox reaction and the best way to balance redox reactions is with the half-reaction method.  Redox reactions must be both mass balanced (same number of each kind of atom) and charge balanced, where the number of electrons &quot;lost&quot; must be the same as the number of electrons &quot;gained&quot;.

Notice that the top equation is multiplied by 6 in order to make the number of electrons gained and lost the same.

6(Fe2+  --&gt; Fe3+ + 1e-)

14H+ +  Cr2O7^2-+ 6e- --&gt; 2Cr^3+  +  7H2O

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14H+ + 6Fe2+ + Cr2O7^2- --&gt; 6Fe3+ + 2Cr3+ + 7H2O

Answer 2

6Fe2+ +14H+ + Cr2O7-2 --------&gt; 2Cr3+ +7H2O +6Fe3+

Answer 3

Hi

Fe2+ ------&gt; Fe3+

Cr2O7-2--------&gt; 2Cr3+

Fe2+ ------&gt; Fe3+

14H+ + Cr2O7-2--------&gt; 2Cr3+ + 7H2O

Fe2+ ------&gt; Fe3+ +e

6e + 14H+ + Cr2O7-2--------&gt; 2Cr3+ + 7H2O

6Fe2+ ------&gt; 6Fe3+ + 6e

6e + 14H+ + Cr2O7-2--------&gt; 2Cr3+ + 7H2O

Balance the electrons

then the 6e both goes and by adding up the 2 half/equation

6Fe2+ +14H+ + Cr2O7-2 --------&gt; 2Cr3+ +7H2O +6Fe3+