Chapter 23, Problem 34QP

Interpretation Introduction

Interpretation:

The given equations are to be completed and balanced.

Concept Introduction: A chemical reaction consists of the atoms or molecules that combine with each other to give a product.

Reactants are written in left side of chemical reaction and products are written in right side of chemical reaction

In a balanced equation, the number of atomsshould be equal on both sides of the reaction.

In the case of a nonbalanced equation, choose big number in front of each atom to do balance equation.

A chemical reaction consists of the atoms or molecules that combine with each other to give a product.

Answer to Problem 34QP

Solution: The complete and balanced equations are represented below:

(a) $2\text{Na}\left(s\right)+2{\text{H}}_{\text{2}}\text{O}\left(l\right)\to 2\text{NaOH}\left(aq\right)+{\text{H}}_{\text{2}}\left(g\right)$

(b) $\text{2NaOH}\left(aq\right)+{\text{CO}}_2\left(g\right)\to {\text{Na}}_2{\text{CO}}_{\text{3}}\left(aq\right)+{\text{H}}_{\text{2}}\text{O}\left(l\right)$

(c) ${\text{Na}}_{\text{2}}{\text{CO}}_3\left(s\right)+2\text{HCl}\left(aq\right)\to 2\text{NaCl}\left(aq\right)+{\text{CO}}_2\left(g\right){\text{+H}}_{\text{2}}\text{O}\left(l\right)$

(d) ${\text{NaHCO}}_3\left(aq\right)+\text{HCl}\left(aq\right)\to \text{NaCl}\left(aq\right)+{\text{CO}}_2\left(g\right)+{\text{H}}_{\text{2}}\text{O}\left(l\right)$

(e) ${\text{2NaHCO}}_3\left(s\right)\to {\text{Na}}_2{\text{CO}}_{\text{3}}\left(s\right)+{\text{CO}}_2\left(g\right){\text{+H}}_{\text{2}}\text{O}\left(l\right)$

(f) ${\text{Na}}_2{\text{CO}}_3\left(s\right)\to$ no reaction

Explanation of Solution

a)Sodium reacts with water

A colorless solution of potassium hydroxide is formed and hydrogen gas is evolved when sodium reacts vigorously with water. The dissolved hydroxide makes the resulting solution basic.

The reaction is as

$2\text{Na}\left(s\right)+2{\text{H}}_{\text{2}}\text{O}\left(l\right)\to 2\text{NaOH}\left(aq\right)+{\text{H}}_{\text{2}}\left(g\right)$.

b)An aqueous solution of $\text{NaOH}$ reacts with ${\text{CO}}_{\text{2}}$.

Sodium carbonateand water are obtained when sodium hydroxide reacts with carbon dioxide.

The reaction is as:

$\text{2NaOH}\left(aq\right)+{\text{CO}}_2\left(g\right)\to {\text{Na}}_2{\text{CO}}_{\text{3}}\left(aq\right)+{\text{H}}_{\text{2}}\text{O}\left(l\right)$.

c)Solid ${\text{Na}}_{\text{2}}{\text{CO}}_3$ reacts with an $\text{HCl}$ solution.

Sodium chloride $\left(\text{NaCl}\right)$, water $\left({\text{H}}_{\text{2}}\text{O}\right)$, and carbon dioxide $\left({\text{CO}}_{\text{2}}\right)$ are obtained by the reaction of solid ${\text{Na}}_{\text{2}}{\text{CO}}_3$ with hydrochloric acid $\left(\text{HCl}\right)$.

The reaction is as

${\text{Na}}_{\text{2}}{\text{CO}}_3\left(s\right)+2\text{HCl}\left(aq\right)\to 2\text{NaCl}\left(aq\right)+{\text{CO}}_2\left(g\right){\text{+H}}_{\text{2}}\text{O}\left(l\right)$.

d)Solid ${\text{NaHCO}}_3$ reacts with $\text{HCl}$.

Sodium chloride $\left(\text{NaCl}\right)$, water $\left({\text{H}}_{\text{2}}\text{O}\right)$, and carbon dioxide $\left({\text{CO}}_{\text{2}}\right)$ are obtained by the reaction of solid sodium bicarbonate $\left({\text{NaHCO}}_3\right)$ with hydrochloric acid $\left(\text{HCl}\right)$.

The reaction is as

${\text{NaHCO}}_3\left(s\right)+\text{HCl}\left(aq\right)\to \text{NaCl}\left(aq\right)+{\text{CO}}_2\left(g\right)+{\text{H}}_{\text{2}}\text{O}\left(l\right)$.

e)Solid ${\text{NaHCO}}_3$ is heated

When solid sodium bicarbonate $\left({\text{NaHCO}}_3\right)$ is heated, it breaks down into sodium carbonate $\left({\text{Na}}_{\text{2}}{\text{CO}}_3\right)$, water $\left({\text{H}}_{\text{2}}\text{O}\right)$, and carbon dioxide $\left({\text{CO}}_{\text{2}}\right)$. This type of reaction is a thermal decomposition reaction.

The reaction is as

${\text{2NaHCO}}_3\left(s\right)\to {\text{Na}}_2{\text{CO}}_{\text{3}}\left(s\right)+{\text{CO}}_2\left(g\right){\text{+H}}_{\text{2}}\text{O}\left(l\right)$.

f)Solid ${\text{Na}}_2{\text{CO}}_3$ is heated

When solid sodium carbonate $\left({\text{Na}}_2{\text{CO}}_3\right)$ is heated, it gives nothing.

The reaction is as:

${\text{Na}}_2{\text{CO}}_3\left(s\right)\to$ no reaction