Question

Use the reaction to answer the question.

Cr2O72−(aq) + H2O(l) ⇄ 2CrO42−(aq)+ 2H+(aq)

Given Cr2O72−ions are orange and CrO42−ions are yellow, which change to the reaction would most effectively make the solution more orange?

(1 point)

adding water

increasing the pH

removing water

decreasing the pH

Answer 1

Decreasing the pH.

Adding H+ (lowering pH) shifts the equilibrium left (Le Chatelier), converting chromate (yellow) to dichromate (orange).