H2+i2= 2hi+3 kcal based on the reaction given above, as the temperature decreases, the formation of the reactants will: a. decrease b. increase c. remained consistent d. indeterminate

Decrease

Explanation:
The reaction given is an exothermic reaction. This means that the heat is a product.
At equilibrium, the rate of forward reaction is equal to the rate of backward reaction.
Now, decreasing the temperature means that the concentration of the products will decrease. 
As a result, the equilibrium will shift to the right leading to the formation of more products in order to reach equilibrium again.
This means that the formation of the reactants will decrease.

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Remember that rust prevented by placing a sacrificial electrode in electrical contact with the iron. the sacrificial electrode must be composed of a metal that  oxidizes  more easily than iron (that is, it must be below iron in table 18.1).