[s3a]

In this question, my teacher wrote that the concentration of product increases but isn't it actually the concentration of REACTANT DECREASING?

Answer he gave us:
"With H+ present, OH will be neutralized into H20. Essentially, we now have increased [product]. In this case, the reverse reaction will be favoured.

SOLUTION IS MORE ORANGE."

[nj_bartel]

Consider LeChatlier's Principle.  What's disappearing initially?  What's increasing?  In what direction will this drive the reaction?

[Borek]

Think in terms of

2CrO₄^2- + 2H⁺ <-> Cr₂O₇^2- + H₂O

[s3a]

Oh wait I think I got it! So, if H20 was not on the product side of the reversible equilibrium then I could state that reactant concentration is decreasing instead of product concentration increasing?