Chapter 12, Problem 20E

(a)

To determine

Correct stock system name for the compound $\text{Zn}{\left({\text{NO}}_{\text{3}}\right)}_2$.

Answer to Problem 20E

The correct stock system name for $\text{Zn}{\left({\text{NO}}_{\text{3}}\right)}_2$ is zinc $\left(\text{II}\right)$ nitrate.

Explanation of Solution

Given Info: The compound is $\text{Zn}{\left({\text{NO}}_{\text{3}}\right)}_2$ and the name of the compound is zinc $\left(\text{II}\right)$ nitrate.

Explanation:

Stock system names are used for different compounds of metals formed with a given non-metal.

The ionic charge of metal is placed in parentheses just after the metal’s name and the name of non-metal or polyatomic ion is written in end.

In the given compound $\text{Zn}{\left({\text{NO}}_{\text{3}}\right)}_2$, there are two nitrate anions and one nitrate anion has one negative charge $\left(-1\right)$. To maintain the charge neutrality of the compound, zinc must have two positive charges $\left(+2\right)$. The charge on metal is placed just after its name in parentheses. Name of the anion is written in the end after the name and charge on metal. Thus, the stock system name for the compound $\text{Zn}{\left({\text{NO}}_{\text{3}}\right)}_2$ is zinc $\left(\text{II}\right)$ nitrate.

Therefore, the given name of the compound $\text{Zn}{\left({\text{NO}}_{\text{3}}\right)}_2$ is correct.

Conclusion:

Therefore, the correct stock system name for $\text{Zn}{\left({\text{NO}}_{\text{3}}\right)}_2$ is zinc $\left(\text{II}\right)$ nitrate.

(b)

To determine

Correct stock system name for the compound $\text{CrS}$.

Answer to Problem 20E

The correct stock system name for $\text{CrS}$ is chromium $\left(\text{II}\right)$ sulfide.

Explanation of Solution

Given Info: The compound is $\text{CrS}$ and the name of the compound is chromium $\left(\text{I}\right)$ sulfide.

Explanation:

Stock system names are used for different compounds of metals formed with a given non-metal.

The ionic charge of metal is placed in parentheses just after the metal’s name and the name of non-metal or polyatomic ion is written in end.

In the given compound $\text{CrS}$, there is one sulfide anion. Sulfide anion has two negative charges $\left(-2\right)$. To maintain the charge neutrality of the compound, chromium must have two positive charges $\left(+2\right)$. The charge on metal is placed just after its name in parentheses. Name of the anion is written in the end after the name and charge on metal. Thus, the stock system name for the compound $\text{CrS}$ is chromium $\left(\text{II}\right)$ sulfide.

The given name of the compound $\text{CrS}$ is chromium $\left(\text{I}\right)$ sulfide. Therefore, the given name of the compound $\text{CrS}$ is incorrect.

Conclusion:

Therefore, the correct stock system name for $\text{CrS}$ is chromium $\left(\text{II}\right)$ sulfide.

(c)

To determine

The correct stock system name for the compound ${\text{Cu}}_{\text{2}}\text{O}$.

Answer to Problem 20E

The correct stock system name for ${\text{Cu}}_{\text{2}}\text{O}$ is copper $\left(\text{I}\right)$ oxide.

Explanation of Solution

Given Info: The compound is ${\text{Cu}}_{\text{2}}\text{O}$ and the name of the compound is copper $\left(\text{II}\right)$ oxide.

Explanation:

Stock system names are used for different compounds of metals formed with a given non-metal.

The ionic charge of metal is placed in parentheses just after the metal’s name and the name of non-metal or polyatomic ion is written in end.

In the given compound ${\text{Cu}}_{\text{2}}\text{O}$, there is one oxide anion. Oxide anion has two negative charges $\left(-2\right)$. To maintain the charge neutrality of the compound, two copper atoms must have net two positive charges $\left(+2\right)$ or in other words, each copper has one positive charge $\left(+1\right)$. The charge on metal is placed just after its name in parentheses. Name of the anion is written in the end after the name and charge on metal. Thus, the stock system name for the compound ${\text{Cu}}_{\text{2}}\text{O}$ is a copper $\left(\text{I}\right)$ oxide.

The given name of the compound ${\text{Cu}}_{\text{2}}\text{O}$ is copper $\left(\text{II}\right)$ oxide. Therefore, the given name of the compound ${\text{Cu}}_{\text{2}}\text{O}$ is incorrect.

Conclusion:

Therefore, the correct stock system name for ${\text{Cu}}_{\text{2}}\text{O}$ is copper $\left(\text{I}\right)$ oxide.