Chapter 7, Problem 13A

Interpretation Introduction

Interpretation:

The unbalanced chemical equation corresponding to the electric decomposition of potassium iodide in water needs to be presented.

Concept Introduction:

• A chemical reaction is expressed as a chemical equation having reactants and products on left and right side of the reaction arrow respectively.

  $\text{Reactants }\to \text{ Products}$

• It also gives the physical state (solid (s), liquid (l), gas (g)) and the amount of reactants and products involved in the reaction.

Answer to Problem 13A

  $\text{KI(s)}+{\text{ H}}_{\text{2}}\text{O(g) }\to {\text{ KOH (aq) + H}}_2\text{(g) + I(s) }$

Explanation of Solution

The given process involves the reaction between potassium iodide solid with water to form aqueous potassium hydroxide, elemental iodine and hydrogen gas. The reactants and products are:

Reactant:

  $\begin{array}{l}\text{Potassium iodide, solid - KI}(\text{s})\\ {\text{Water - H}}_{\text{2}}\text{O (l)}\end{array}$

Products:

  $\begin{array}{l}\text{Potassium hydroxide, aqueous - KOH(aq)}\\ {\text{Hydrogen, gas - H}}_{\text{2}}\text{(g)}\\ \text{Iodine, solid - I (s)}\end{array}$

Unbalanced equation:

  $\text{KI(s)}+{\text{ H}}_{\text{2}}\text{O(g) }\to {\text{ KOH (aq) + H}}_2\text{(g) + I(s) }$

Conclusion

Therefore the unbalanced reaction will have solid potassium iodide and water as the reactants with aqueous potassium hydroxide, elemental iodine and hydrogen gas as the products.