Chapter U1.23, Problem 3E

Interpretation Introduction

(a)

Interpretation:

Charge on Hg ion of HgS must be found out. The name of the compound must also be given.

Concept introduction:

A compound is formed from atoms of different elements such that the overall charge on the compound is neutral.

Answer to Problem 3E

The charge on mercury ion in HgS is + 2.

The name of the compound is mercuric sulfide.

Explanation of Solution

Mercury is in + 2 oxidation state and sulfur is in -2 oxidation state. ${\text{S}}^{2-}$ is known as sulfide ion. Thus, the name of the compound is mercuric sulfide or mercury(II) sulfide.

Interpretation Introduction

(b)

Interpretation:

The charge on the copper ion of CuCO₃ must be found out.

Concept introduction:

A compound is formed from atoms of different elements such that the overall charge on the compound is neutral.

Answer to Problem 3E

The charge on the copper ion is + 2. The name of the compound is copper (II) carbonate.

Explanation of Solution

The given compound is CuCO₃. Here, the charge on the carbonate ion is -2, thus, to form a compound in which copper and carbonate are in 1:1 ratio, the charge on the Cu should be + 2. The name of the compound will be cupric (II) carbonate or copper carbonate.

Interpretation Introduction

(c)

Interpretation:

Charge on nickel ion in NiCl₂ must be found out.

Concept introduction:

A compound is formed from atoms of different elements such that the overall charge on the compound is neutral.

Answer to Problem 3E

The charge on nickel ion is + 2. The name of the compound is nickel (II) chloride.

Explanation of Solution

As chlorine belongs to the halogen family thus, it will have -1 charge. In the neutral compound, ${\text{NiCl}}_{\text{2}}$, 2 Cl ions are reacting with 1 Ni ion.

Thus, the charge on Ni should be + 2 to form a neutral compound. The name of the compound will be nickel (II) chloride.

Interpretation Introduction

(d)

Interpretation:

Charge on cobalt ion in $\text{Co}{\left({\text{NO}}_{\text{3}}\right)}_{\text{3}}$ must be found out.

Concept introduction:

A compound is formed from atoms of different elements such that the overall charge on the compound is neutral.

Answer to Problem 3E

The charge on cobalt ion is + 3. The name of the compound is cobalt (III) nitrate.

Explanation of Solution

The given compound is $\text{Co}{\left({\text{NO}}_{\text{3}}\right)}_{\text{3}}$, here, the anion is ${\text{NO}}_3{}^{-}$ which is nitrate ion. Now, to from the neutral compound, the ratio of Co ion to ${\text{NO}}_{\text{3}}{}^{\text{-}}$ ion is 1:3 thus, the charge on the cobalt must be + 3.

The name of the compound will be cobalt (III) nitrate.

Interpretation Introduction

(e)

Interpretation:

The charge on the copper ion of $\text{Cu}{\left(\text{OH}\right)}_{\text{2}}$ must be found out.

Concept introduction:

A compound is formed from atoms of different elements such that the overall charge on the compound is neutral.

Answer to Problem 3E

The charge on Cu is + 2 and the name of the compound is cupric hydroxide.

Explanation of Solution

The given compound is $\text{Cu}{\left(\text{OH}\right)}_{\text{2}}$, here, hydroxide ion is represented as ${\text{OH}}^{-}$. In the compound, Cu and OH are in 1:2 ratio thus, the charge on the Cu must be + 2.

The name of the compound is cupric hydroxide or copper (II) hydroxide.

Interpretation Introduction

(f)

Interpretation:

The charge on the iron ion of ${\text{FeSO}}_{\text{4}}$ must be found out.

Concept introduction:

A compound is formed from atoms of different elements such that the overall charge on the compound is neutral.

Answer to Problem 3E

The charge on the iron ion is + 2. The name of the compound is ferrous sulfate.

Explanation of Solution

The given compound is ${\text{FeSO}}_{\text{4}}$. Here, the anion is sulfate with -2 charge. From the formula, Fe and sulfate ion are in 1:1 ratio thus, the charge on Fe will be + 2.

The name of the compound will be ferrous sulfate or iron (II) sulfate.