Chapter 7, Problem 16A

Interpretation Introduction

Interpretation:

The unbalanced chemical equation corresponding to reaction of calcium metal with 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 16A

  ${\text{Ca(s) + H}}_{\text{2}}\text{O(l) }\to {\text{ H}}_{\text{2}}{\text{(g) + Ca(OH)}}_{\text{2}}\text{(s) }$

Explanation of Solution

The given process involves the reaction between calcium metal with water to form hydrogen gas and solid calcium hydroxide. The reactants and products are:

Reactants:

  $\begin{array}{l}\text{Calcium, solid - Ca}(\text{s})\\ {\text{Water, liquid - H}}_{\text{2}}\text{O (l)}\end{array}$

Products:

  $\begin{array}{l}{\text{Hydrogen, gas - H}}_{\text{2}}\text{(g)}\\ {\text{Calcium hydroxide, solid - Ca(OH)}}_{\text{2}}\text{ (s)}\end{array}$

Unbalanced equation:

  ${\text{Ca(s) + H}}_{\text{2}}\text{O(l) }\to {\text{ H}}_{\text{2}}{\text{(g) + Ca(OH)}}_{\text{2}}\text{(s) }$

Conclusion

Therefore the unbalanced reaction will have solid calcium metal and water as the reactants with hydrogen gas and solid calcium hydroxideas the products.