Chapter 19, Problem 55A

a.

Interpretation Introduction

Interpretation : The balanced equation for the reaction of lithium metal with water is to be written.

Concept Introduction : A chemical equation is balanced if it has an equal atom count on the product and reactant sides for each element taking place in the chemical reaction.

Answer to Problem 55A

The balanced equation for the reaction of lithium metal with water is given as $2\text{Li}\left(s\right)\text{+}2{\text{H}}_2\text{O}\left(l\right)\to 2\text{LiOH}\left(aq\right)\text{+}{\text{H}}_{\text{2}}\left(g\right)$ .

Explanation of Solution

Lithium belongs to the Group 1A element.

Group 1 A elements react vigorously with water since they are alkali metals.

When lithium metal reacts with water, an aqueous solution of lithium hydroxide and hydrogen gas is produced.

  $\text{Li}\left(s\right)\text{+}{\text{H}}_2\text{O}\left(l\right)\to \text{LiOH}\left(aq\right)\text{+}{\text{H}}_{\text{2}}\left(g\right)$

The completed balanced reaction is given below:

  $2\text{Li}\left(s\right)\text{+}2{\text{H}}_2\text{O}\left(l\right)\to 2\text{LiOH}\left(aq\right)\text{+}{\text{H}}_{\text{2}}\left(g\right)$

b.

Interpretation Introduction

Interpretation : The balanced equation for the reaction of barium metal with water is to be written.

Concept Introduction : A chemical equation is balanced if it has an equal atom count on the product and reactant sides for each element taking place in the chemical reaction.

Answer to Problem 55A

The balanced equation for the reaction of barium metal with water is given as $2\text{Ba}\left(s\right)\text{+}2{\text{H}}_2\text{O}\left(l\right)\to \text{Ba}{\left(\text{OH}\right)}_2\left(aq\right)\text{+}{\text{H}}_{\text{2}}\left(g\right)$ .

Explanation of Solution

Barium belongs to the Group 2A element.

Group 2 A elements react fast with water since they are alkaline earth metals.

When barium metal reacts with water, an aqueous solution of barium hydroxide and hydrogen gas is produced.

  $2\text{Ba}\left(s\right)\text{+}{\text{H}}_2\text{O}\left(l\right)\to 2\text{Ba}{\left(\text{OH}\right)}_2\left(aq\right)\text{+}{\text{H}}_{\text{2}}\left(g\right)$

The completed balanced reaction is given below:

  $2\text{Ba}\left(s\right)\text{+}2{\text{H}}_2\text{O}\left(l\right)\to 2\text{Ba}{\left(\text{OH}\right)}_2\left(aq\right)\text{+}{\text{H}}_{\text{2}}\left(g\right)$