Chapter 3, Problem 31P

3-47 Answer true or false.

(a) The name of a binary ionic compound consists of the name of the positive ion followed by the name of the negative ion.

(b) In naming binary ionic compounds, it is necessary to state the number of each ion present in the compound.

(c) The formula of aluminum oxide is AL₂O₃.

(d) Both copper(II) oxide and cupric oxide are acceptable names for CuO.

(e) The systematic name for Fe₂O₃ is iron(II) oxide.

(f) The systematic name for FeCO₃ is ironcarbonate.

(g) The systematic name for NaH₂PO₄ is sodium dihydrogen phosphate.

(h) The systematic name for K,HPO₄ is dipotassium hydrogen phosphate.

(i) The systematic name for Na20 is sodium oxide.

(j) The systematic name for PCL3 is potassium chloride.

(k) The formula of ammonium carbonate is NH₄CO₃.

Interpretation Introduction

(a)

Interpretation:

To analyse whether the given statement -The name of a binary ionic compound consists of the name of the positive ion followed by the name of the negative ion, is true or not.

Concept Introduction:

A covalent bond is formed by sharing of same number of electrons between two atoms to complete their octet. Atoms taking part in covalent bond formation may share one, two or three electron pairs thus forming single, double and triple bond respectively.

A binary covalent compound contains two kinds of atoms.

A covalent compound can be made of a atoms of the same element like Hydrogen, Oxygen etc, or it may be formed by atoms of different elements like $\text{H}\text{C}\text{l}$, ${\text{H}}_2\text{O}$etc.

According to the rules for naming, binary covalent compound is named in this order-first the less electronegative element and then the more electronegative element.

Answer to Problem 31P

The name of a binary ionic compound consists of the name of the positive ion followed by the name of the negative ion. Thus, the statement is true.

Explanation of Solution

According to the rules for naming, binary covalent compound is named in this order-first the less electronegative element and then the more electronegative element.

For Example- $B\text{e}{\text{F}}_2$

Electronic configuration of Beryllium, 2,2.

Valence shell has 2 electrons.

But to follow octet rule valance shall requires 8 electrons, for that it donates its 1 electron to two fluorine each.

On ejecting of 2 electrons now valence shell for Beryllium counts only 2 electrons, which completes its duplet. Hence it follows the octet rule.

Since, beryllium forms a cation it is written first, and Fluorine forming an anion is written later.

Therefore, the name of a binary ionic compound consists of the name of the positive ion followed by the name of the negative ion.

Interpretation Introduction

(b)

Interpretation:

To analyse whether the given statement -In naming binary ionic compounds, it is necessary to state the number of each ion present in the compound, is true or not.

Concept Introduction:

Binary compounds are those compounds which have atoms of two different elements. Since, the compounds are different, there is some difference in the electronegativity in the atoms and generally formation of a polar covalent bond takes place.

Binary compounds may or may not have the same ratio in all the existing atoms. For example: carbon monoxide, CO contains 1 carbon and 1 oxygen atom but carbon dioxide ${\text{CO}}_{\text{2}}$contains 1 carbon atom and 2 oxygen atoms.

Answer to Problem 31P

In naming binary ionic compounds, it is necessary to state the number of each ion present in the compound. Thus, the statement is true.

Explanation of Solution

Binary compounds may or may not have the same ratio in all the existing compound.

For example: carbon monoxide, CO contains 1 carbon and 1 oxygen atom but carbon dioxide ${\text{CO}}_{\text{2}}$contains 1 carbon atom and 2 oxygen atoms. Binary ionic compounds may or may not have the same ratio in all the existing compound.

For example: In Iron (II) oxide, FeO, the ratio of Iron and Oxygen is 1:1 but in Iron (III) oxide, ${\text{Fe}}_{\text{2}}{\text{O}}_{\text{3}}$, the ratio of Iron and Oxygen is 2:3.

Therefore. in naming binary ionic compounds, it is necessary to state the number of each ion present in the compound.

Interpretation Introduction

(c)

Interpretation:

To analyse whether the given statement -The formula of aluminium oxide is $\text{a}{\text{l}}_2{\text{O}}_3$, is true or not.

Concept Introduction:

Binary compounds are those compounds which have atoms of two different elements. Since the compounds are different, there is some difference in the electronegativity in the atoms and generally formation of a polar covalent bond takes place.

In ionic compounds, there formula is calculated by multiplication of valences.

Answer to Problem 31P

The formula of aluminium oxide is $\text{a}{\text{l}}_2{\text{O}}_3$. Thus, the statement is true.

Explanation of Solution

Binary compounds are those compounds which have atoms of two different elements. Since the compounds are different, there is some difference in the electronegativity in the atoms and generally formation of a polar covalent bond takes place.

In ionic compounds, there formula is calculated by multiplication of valences. The naming of ionic compounds is done by crisscross method. Here, Al has +3 charge and oxygen has -2 charge thus, there will be 2 aluminum atoms and 3 oxygen atoms in the compound.

$\begin{array}{l}\text{a}\text{l} \text{O}\\ \xcancel{}\\ 3 2\end{array}$

The formula of aluminium oxide is $\text{a}{\text{l}}_2{\text{O}}_3$.

Interpretation Introduction

(d)

Interpretation:

To analyse whether the given statement -Both copper (II) oxide and cupric oxide are acceptable names for $\text{C}u\text{O}$, is true or not.

Concept Introduction:

Binary compounds are those compounds which have atoms of two different elements. Since the compounds are different, there is some difference in the electronegativity in the atoms and generally formation of a polar covalent bond takes place.

In ionic compounds, there formula is calculated by multiplication of valences.

Answer to Problem 31P

Both copper (II) oxide and cupric oxide are acceptable names for $\text{C}u\text{O}$. Thus, the statement is true.

Explanation of Solution

Binary compounds are those compounds which have atoms of two different elements. Since the compounds are different, there is some difference in the electronegativity in the atoms and generally formation of a polar covalent bond takes place.

In ionic compounds, there formula is calculated by multiplication of valences.

Therefore, both copper (II) oxide and cupric oxide are acceptable names for $\text{C}u\text{O}$.

Interpretation Introduction

(e)

Interpretation:

To analyse whether the given statement -The systematic name for $\text{F}{\text{e}}_2{\text{O}}_3$is Iron (II) oxide, is true or not.

Concept Introduction:

Binary compounds are those compounds which have atoms of two different elements. Since the compounds are different, there is some difference in the electronegativity in the atoms and generally formation of a polar covalent bond takes place.

In ionic compounds, there formula is calculated by multiplication of valences.

Answer to Problem 31P

The systematic name for $\text{F}{\text{e}}_2{\text{O}}_3$is Iron (III) oxide. Thus, the statement is false.

Explanation of Solution

Binary compounds are those compounds which have atoms of two different elements. Since the compounds are different, there is some difference in the electronegativity in the atoms and generally formation of a polar covalent bond takes place.

In ionic compounds, there formula is calculated by multiplication of valences.

Iron (II) oxide.

$\begin{array}{l}\text{F}\text{e} \text{O}\\ \xcancel{}\\ 2 2\end{array}$

The systematic name for $\text{F}\text{e}\text{O}$is Iron (II) oxide.

$\begin{array}{l}\text{F}\text{e} \text{O}\\ \xcancel{}\\ 3 2\end{array}$

The systematic name for $\text{F}{\text{e}}_2{\text{O}}_3$is Iron (III) oxide.

Interpretation Introduction

(f)

Interpretation:

To analyse whether the given statement -The systematic name for $\text{F}\text{e}\text{C}{\text{O}}_3$is Iron carbonate, is true or not.

Concept Introduction:

Binary compounds are those compounds which have atoms of two different elements. Since the compounds are different, there is some difference in the electronegativity in the atoms and generally formation of a polar covalent bond takes place.

In ionic compounds, there formula is calculated by multiplication of valences.

Answer to Problem 31P

The systematic name for $\text{F}\text{e}\text{C}{\text{O}}_3$is Iron (II) carbonate. Thus, the statement is false.

Explanation of Solution

Binary compounds are those compounds which have atoms of two different elements. Since the compounds are different, there is some difference in the electronegativity in the atoms and generally formation of a polar covalent bond takes place.

In ionic compounds, there formula is calculated by multiplication of valences.

$\begin{array}{l}\text{F}\text{e} \text{C}{\text{O}}_3{}^{2-}\\ \xcancel{}\\ 2 2\end{array}$

The systematic name for $\text{F}\text{e}\text{C}{\text{O}}_3$is Iron (II) carbonate.

Interpretation Introduction

(g)

Interpretation:

To analyse whether the given statement -The systematic name for $\text{N}\text{a}{\text{H}}_{2}P{\text{O}}_4$is Sodium.

dihydrogen phosphate is true or not.

Concept Introduction:

Binary compounds are those compounds which have atoms of two different elements. Since the compounds are different, there is some difference in the electronegativity in the atoms and generally formation of a polar covalent bond takes place.

In ionic compounds, there formula is calculated by multiplication of valences.

Answer to Problem 31P

The systematic name for $\text{N}\text{a}{\text{H}}_{2}P{\text{O}}_4$is Sodium dihydrogen phosphate. Thus, the statement is true.

Explanation of Solution

Binary compounds are those compounds which have atoms of two different elements. Since the compounds are different, there is some difference in the electronegativity in the atoms and generally formation of a polar covalent bond takes place.

In ionic compounds, there formula is calculated by multiplication of valences.

$\begin{array}{l}\text{N}\text{a} {\text{H}}_{2}P{\text{O}}_4{}^{-}\\ \xcancel{}\\ 1 1\end{array}$

The systematic name for $\text{N}\text{a}{\text{H}}_{2}P{\text{O}}_4$is Sodium dihydrogen phosphate.

Interpretation Introduction

(h)

Interpretation:

To analyse whether the given statement -The systematic name for $K_2\text{H}P{\text{O}}_4$is dipotassium hydrogen phosphate, is true or not.

Concept Introduction:

Binary compounds are those compounds which have atoms of two different elements. Since the compounds are different, there is some difference in the electronegativity in the atoms and generally formation of a polar covalent bond takes place.

In ionic compounds, there formula is calculated by multiplication of valences.

Answer to Problem 31P

The systematic name for $K_2\text{H}P{\text{O}}_4$is Sodium dipotassium hydrogen phosphate. Thus, the statement is true.

Explanation of Solution

Binary compounds are those compounds which have atoms of two different elements. Since the compounds are different, there is some difference in the electronegativity in the atoms and generally formation of a polar covalent bond takes place.

In ionic compounds, there formula is calculated by multiplication of valences.

$\begin{array}{l}K \text{H}P{\text{O}}_4{}^{2-}\\ \xcancel{}\\ 1 2\end{array}$

The systematic name for $K_2\text{H}P{\text{O}}_4$is Sodium dipotassium hydrogen phosphate.

Interpretation Introduction

(i)

Interpretation:

To analyse whether the given statement -The systematic name for $\text{N}{\text{a}}_2\text{O}$is Sodium oxide, is true or not.

Concept Introduction:

Binary compounds are those compounds which have atoms of two different elements. Since the compounds are different, there is some difference in the electronegativity in the atoms and generally formation of a polar covalent bond takes place.

In ionic compounds, there formula is calculated by multiplication of valences.

Answer to Problem 31P

The systematic name for $\text{N}{\text{a}}_2\text{O}$is Sodium oxide. Thus, the statement is true.

Explanation of Solution

Binary compounds are those compounds which have atoms of two different elements. Since the compounds are different, there is some difference in the electronegativity in the atoms and generally formation of a polar covalent bond takes place.

In ionic compounds, there formula is calculated by multiplication of valences.

$\begin{array}{l}\text{N}\text{a} \text{O}\\ \xcancel{}\\ 1 2\end{array}$

The systematic name for $\text{N}{\text{a}}_2\text{O}$is Sodium oxide.

Interpretation Introduction

(j)

Interpretation:

To analyse whether the given statement -The systematic name for $P\text{C}{\text{l}}_3$is Potassium chloride, is true or not.

Concept Introduction:

Binary compounds are those compounds which have atoms of two different elements. Since the compounds are different, there is some difference in the electronegativity in the atoms and generally formation of a polar covalent bond takes place.

Answer to Problem 31P

The systematic name for $P\text{C}{\text{l}}_3$is Potassium trichloride. Thus, the statement is false.

Explanation of Solution

A binary compound may or may not have same ratio of the atoms of the elements in the existing compounds.

The ratio of Phosphorous and chlorine in Phosphorous (III) Chloride is 1:3 Therefore, systematic name for $P\text{C}{\text{l}}_3$is Potassium trichloride.

Interpretation Introduction

(k)

Interpretation:

To analyse whether the given statement -The formula of ammonium carbonate is $\text{N}{\text{H}}_4\text{C}{\text{O}}_3$, is true or not.

Concept Introduction:

Binary compounds are those compounds which have atoms of two different elements. Since the compounds are different, there is some difference in the electronegativity in the atoms and generally formation of a polar covalent bond takes place.

In ionic compounds, there formula is calculated by multiplication of valences.

Answer to Problem 31P

The formula of ammonium carbonate is $\text{N}{\text{H}}_4\text{C}{\text{O}}_3$. Thus, the statement is correct.

Explanation of Solution

Binary compounds are those compounds which have atoms of two different elements. Since the compounds are different, there is some difference in the electronegativity in the atoms and generally formation of a polar covalent bond takes place.

In ionic compounds, there formula is calculated by multiplication of valences.

$\begin{array}{l}\text{N}{\text{H}}_4{}^{+} \text{C}{\text{O}}_3{}^{-}\\ \xcancel{}\\ 1 2\end{array}$

The formula of ammonium carbonate is $\text{N}{\text{H}}_4\text{C}{\text{O}}_3$.