Chapter 16.3, Problem 16.4P

(a)

Interpretation Introduction

Interpretation:

Shift of equilibrium with increase in dichromate ion in below reaction has to be determined.

  $2{\text{CrO}}_{\text{4}}^{\text{2-}}\left(\text{aq}\right)+2{\text{H}}^{\text{+}}\left(\text{aq}\right)\rightleftharpoons {\text{Cr}}_{\text{2}}{\text{O}}_{\text{7}}^{\text{2-}}\left(\text{aq}\right)+{\text{H}}_{\text{2}}\text{O}\left(\text{l}\right)$

Concept Introduction:

Le Chatelier’s principle states that changes at equilibrium in system respond to reduce the changes and bring back the system to restore its equilibrium under new conditions. According to this principle with increase in concentration of reactants the reaction moves towards forward direction thus this increases the concentration of products. Whereas with increase in concentration of product reaction shifts towards reverse direction. This increases the concentration of reactants.

(b)

Interpretation Introduction

Interpretation:

Shift of equilibrium with addition of $\text{HCl}$ in below reaction has to be determined.

  $2{\text{CrO}}_{\text{4}}^{\text{2-}}\left(\text{aq}\right)+2{\text{H}}^{\text{+}}\left(\text{aq}\right)\rightleftharpoons {\text{Cr}}_{\text{2}}{\text{O}}_{\text{7}}^{\text{2-}}\left(\text{aq}\right)+{\text{H}}_{\text{2}}\text{O}\left(\text{l}\right)$

Concept Introduction:

Refer to part (a).