Chapter 10, Problem 5PEB

(a)

To determine

Whether the reactionis “combination, decomposition, replacement, or ion exchange reactions.

${\text{ZnCO}}_{\text{3}}\left(\text{s}\right)\to \text{ZnO}\left(\text{s}\right){\text{+CO}}_{\text{2}}\uparrow$

Answer to Problem 5PEB

Solution:

Decomposition

Explanation of Solution

Introduction:

Ion exchange reaction: When ions of two different chemical compounds react with each other forming either aprecipitate, water or a gas, the reaction is known as an ion exchange reaction.

Decomposition: In this reaction the molecule decomposes into two or more different molecules.

Combination reaction: In this reaction two different molecules are combined to form a new molecule.

Replacement: In this type of reaction, one atom is replaced by another atom.

Explanation:

Recall the chemical reaction:

${\text{ZnCO}}_{\text{3}}\left(\text{s}\right)\to \text{ZnO}\left(\text{s}\right){\text{+CO}}_{\text{2}}\uparrow$

Here, the molecule ${\text{ZnCO}}_3$ decomposed into $\text{ZnO}$ and ${\text{CO}}_2$.

Conclusion:

The reaction is a decomposition reaction as a molecule decomposesinto two molecules.

(b)

To determine

Whether the reaction is “combination, decomposition, replacement, or ion exchange reactions.

$\text{2NaBr}\left(aq\right)+{\text{Cl}}_{\text{2}}\left(g\right)\to \text{2NaCl}\left(aq\right){\text{+Br}}_{\text{2}}\left(g\right)\uparrow$

Answer to Problem 5PEB

Solution:

Replacement

Explanation of Solution

Introduction:

Ion exchange reaction: When ions of two different chemical compounds react with each other forming either aprecipitate, water or a gas, the reaction is known as an ion exchange reaction.

Decomposition: In this reaction the molecule decomposes into two or more different molecules.

Combination reaction: In this reaction two different molecules are combined to form a new molecule.

Replacement: In this type of reaction the one atom is replaced by another atom.

Explanation:

Recall the chemical reaction:

$\text{2NaBr}\left(aq\right)+{\text{Cl}}_{\text{2}}\left(g\right)\to \text{2NaCl}\left(aq\right){\text{+Br}}_{\text{2}}\left(g\right)\uparrow$

Here, the atom $\text{Br}$ is replaced by $\text{Cl}$.

Conclusion:

The reaction is a replacement reaction as an atom is replaced by another atom.

(c)

To determine

Whether the reaction is “combination, decomposition, replacement, or ion exchange reactions.

$\text{2Al}\left(s\right)+3{\text{Cl}}_{\text{2}}\left(g\right)\to {\text{2AlCl}}_{\text{3}}\left(s\right)$

Answer to Problem 5PEB

Solution:

Combination

Explanation of Solution

Introduction:

Ion exchange reaction: When ions of two different chemical compounds react with each other forming either aprecipitate, water or a gas, the reaction is known as an ion exchange reaction.

Decomposition: In this reaction the molecule decomposes into two or more different molecules.

Combination reaction: In this reaction, two different molecules are combined to form a new molecule.

Replacement: In this type of reaction, one atom is replaced by another atom.

Explanation:

Recall the chemical reaction:

$\text{2Al}\left(s\right)+3{\text{Cl}}_{\text{2}}\left(g\right)\to {\text{2AlCl}}_{\text{3}}\left(s\right)$

Here, the atom $\text{Al}$ combines with ${\text{Cl}}_{\text{2}}$ molecules to form ${\text{AlCl}}_3$.

Conclusion:

The reaction is a combination reaction as anatom and a gas molecule combines to form a different molecule.

(d)

To determine

Whether the reaction is “combination, decomposition, replacement, or ion exchange reactions.

$\text{Ca}{\left(\text{OH}\right)}_2\left(aq\right)+{\text{H}}_{\text{2}}{\text{SO}}_{\text{4}}\left(aq\right)\to {\text{CaSO}}_{\text{4}}\left(aq\right)+2{\text{H}}_{\text{2}}\text{O}\left(l\right)$

Answer to Problem 5PEB

Solution:

Ion exchange reaction

Explanation of Solution

Introduction:

Ion exchange reaction: When ions of two different chemical compounds react with each other forming either aprecipitate, water or a gas, the reaction is known as an ion exchange reaction.

Decomposition: In this reaction the molecule decomposes into two or more different molecules.

Combination reaction: In this reaction, two different molecules are combined to form a new molecule.

Replacement: In this type of reaction, one atom is replaced by another atom.

Explanation:

Recall the chemical reaction:

$\text{Ca}{\left(\text{OH}\right)}_2\left(aq\right)+{\text{H}}_{\text{2}}{\text{SO}}_{\text{4}}\left(aq\right)\to {\text{CaSO}}_{\text{4}}\left(aq\right)+2{\text{H}}_{\text{2}}\text{O}\left(l\right)$

Here, ${\text{SO}}_4^{2-}$ ion exchanged in the reaction to form ${\text{CaSO}}_{\text{4}}\left(aq\right)$.

Conclusion:

The reaction is anion exchange reaction as ion is exchanged in this reaction.

(e)

To determine

Whether the reaction is “combination, decomposition, replacement, or ion exchange reactions.

$\text{Pb}{\left({\text{NO}}_3\right)}_2\left(aq\right)+{\text{H}}_{\text{2}}\text{S}\left(aq\right)\to 2{\text{HNO}}_{\text{3}}\left(aq\right)+\text{PbS}\downarrow$

Answer to Problem 5PEB

Solution:

Precipitation reaction

Explanation of Solution

Introduction:

Ion exchange reaction: When ions of two different chemical compounds react with each other forming either aprecipitate, water or a gas, the reaction is known as an ion exchange reaction.

Decomposition: In this reaction the molecule decomposes into two or more different molecules.

Combination reaction: In this reaction two different molecules are combined to form a new molecule.

Replacement: In this type of reaction the one atom is replaced by another atom.

Explanation:

Recall the chemical reaction:

$\text{Pb}{\left({\text{NO}}_3\right)}_2\left(aq\right)+{\text{H}}_{\text{2}}\text{S}\left(aq\right)\to 2{\text{HNO}}_{\text{3}}\left(aq\right)+\text{PbS}\downarrow$

Here, a precipitate, $PbS$ is formed in the given reaction. Thus, the given reaction is a precipitation reaction.

Conclusion:

The reaction is a precipitation reaction as a precipitate is formed in this reaction.

(f)

To determine

Whether the reaction is “combination, decomposition, replacement, or ion exchange reactions.

$\text{C}\left(s\right)\text{+ZnO}\left(s\right)\to \text{Zn}\left(s\right)\text{+CO}\uparrow$

Answer to Problem 5PEB

Solution:

Replacement

Explanation of Solution

Introduction:

Ion exchange reaction: When ions of two different chemical compounds react with each other forming either aprecipitate, water or a gas, the reaction is known as an ion exchange reaction.

Decomposition: In this reaction the molecule decomposes into two or more different molecules.

Combination reaction: In this reaction two different molecules are combined to form a new molecule.

Replacement: In this type of reaction the one atom is replaced by another atom.

Explanation:

Recall the chemical reaction:

$\text{C}\left(s\right)\text{+ZnO}\left(s\right)\to \text{Zn}\left(s\right)\text{+CO}\uparrow$

Here, the atom $\text{Zn}$ is replaced by $\text{C}$.

Conclusion:

The reaction is a replacement reaction as an atom is replaced by another atom.