[Rutherford]

Cr₂O₇^2-+2OH^- 2CrO₄^2-+H₂O
In what direction shall the equilibrium state shift upon the addition of water?

I would say that water concentration change is negligible when compared to its total concentration, but as it is a product here, the equilibrium could be also shifted to left by little. When I saw the answer I was surprised that it actually shifts to the right. How is this possible?

[Borek]

Think dilution.

[Rutherford]

You mean that the concentration decreases. If I double the amount of water the concentration for the dichromate ion it will decrease 2 times and for the hydroxy anion 4 times, while for the chromate ion 4 times, too. But again it should shift to the left as 1/8<1/4.

[Borek]

If I double the amount of water the concentration for the dichromate ion it will decrease 2 times and for the hydroxy anion 4 times

4 times?

[Rutherford]

I mistaken, everything lowers its concentration by the factor of 2, but again I have the same situation. Can't see why it would shift to the right.

[curiouscat]

I mistaken, everything lowers its concentration by the factor of 2, but again I have the same situation. Can't see why it would shift to the right.

Even water?

[Rutherford]

I didn't mean for water. For water it doesn't change.