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Explanation of chromate-dichromate equilibrium.

See attached file for full problem description.

1. How does the (H+) of the solution affect the CrO42-/Cr2O72- eqiuilibrium?

2. What poof was shown that CrO42- ions exist in a solution of K2Cr2O7.

3. In what way does OH- affect the equilibrium? Give two methods by which this ion upsets the equilibrium?

4. Write the equations for the equilibrium, showing

a) the reaction between H+ and CrO42- to produce Cr2O72- and H2O

b) the reaction between OH- and Cr2O72- to produce CrO42- and H2O

c) a summation equation showing both H+ and OH - in the equilibrium reaction between CrO42- and Cr2O72- ions.

5. Explain fully what happens when H+ is added to a mixture containing BaCrO4(s) and CrO42-(aq).

6. In effect what was occurring in steps 7 and 8?

7. Explain the general effect of the acids and bases added in part III.

8. If all the bases have OH- (aq) in common, then explain why NH3(aq) acts like a base.

9. Explain why Ca(OH)2 has little effect on the equilibrium.

Is it because it is moderately soluble?

10. Why does C2H5OH not affect the equilibrium?

11. List the conclusions for this experiment, based on le Chatelier's principle.

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If we dissolve potassium chromate in water the resulting solution is YELLOW due to the presence of chromate ions CrO42- ions. But if ...

Solution Summary

A complete explanation of the chromate-dichromate equilibrium supported by chemical reactions is given. 11 questions with step by step explanation are given. Conclusions based on Le Chatelier's principle are discussed.

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