How to balance Cr3+ + ClO3- + H2O → Cr2O72- + Cl- + H+

[Gliese123]

Homework Statement

Hi. :) I'm supposed to balance the formula and write the values.

Cr³⁺+CIO₃^-+H₂O → Cr₂O_7^2-+Cl^-+H⁺

Specify:Amount of electrons
and: Charges

The Attempt at a Solution

I don't really got any clue. Please help!
Cr³⁺ have +3
The oxygen have -2 and then?
Cr³⁺+CIO₃^-+H₂O → Cr₂O_7^2-+Cl^-+H⁺ ?

 

[Borek]

I guess you are trying to assign oxidation numbers. Just follow the rules.

Balancing an equation of the chemical redox reaction with oxidation numbers.