Chapter 12, Problem 42E

Interpretation Introduction

(a)

Interpretation:

Whether the statement “A single bond between carbon and nitrogen is polar” is true or false is to be stated.

Concept introduction:

The polar bond is a type of covalent bond. It is a bond in which the electrons are shared unequally between the two atoms because of which one atom becomes partially negative and the other becomes partially positive.

Answer to Problem 42E

The statement “A single bond between carbon and nitrogen is polar” is true.

Explanation of Solution

In the molecule of $\text{C-N}$, due to the electronegativity difference between the nitrogen and carbon atom, the bonding electron pairs are attracted towards the nitrogen. So, the bonding electrons give a partial negative charge on the nitrogen atom.

Therefore, the $\text{C-N}$ molecule is a polar molecule.

Conclusion

The given statement is true.

Interpretation Introduction

(b)

Interpretation:

Whether the statement “A bond between phosphorus and sulfur will be less polar than a bond between phosphorus and chlorine” is true or false is to be stated.

Concept introduction:

The polar bond is a type of covalent bond. It is a bond in which the electrons are shared unequally between the two atoms because of which one atom becomes partially negative and the other becomes partially positive.

Answer to Problem 42E

The statement “A bond between phosphorus and sulfur will be less polar than a bond between phosphorus and chlorine” is true.

Explanation of Solution

The strength of the polarity between bonds is based on the electronegativity of the bond. The difference in electronegativity between the atoms of phosphorus and chlorine is $0.2$.

On the other hand, the difference in electronegativity between the atoms of phosphorus and sulfur is $0.3$.

$0.3>0.2$

Therefore, $\text{P}-\text{S}$ bond is more polar than $\text{P}-\text{Cl}$ bond.

Conclusion

The given statement is true.

Interpretation Introduction

(c)

Interpretation:

Whether the statement “The electronegativity of calcium is less than the electronegativity of aluminum” is true or false is to be stated.

Concept introduction:

Electronegativity is defined as the tendency of an atom to attract electrons towards it. Polarized bonds are a result of the electronegativity difference between bonding atoms. If the electronegativity difference is $0$, the bond is known as nonpolar covalent bond. If it’s between $0$ to $2.1$, the bond is known as polar covalent bond and if its more than $2.1$, the bond is known as ionic bond.

Answer to Problem 42E

The statement “The electronegativity of calcium is less than the electronegativity of aluminum” is true.

Explanation of Solution

Electronegativity is the capability of an atom to attract the shared pair of electron towards itself.

On moving left to right in a period, the electronegativity increases.

Since, calcium is a $s-$ block element, so, it is electropositive. On the other hand, aluminum is a $p-$ block element, so, it is electronegative.

Therefore, aluminum is more electronegative than calcium.

Conclusion

The given statement is true.

Interpretation Introduction

(d)

Interpretation:

Whether the statement “Strontium $\left(\text{Z}=38\right)$ ions, ${\text{Sr}}^{\text{2+}}$, are isoelectronic with bromide ions, ${\text{Br}}^{-}$” is true or false is to be stated.

Concept introduction:

The ions or atoms which possess the same electron configuration are known as the isoelectronic species. The meaning of isoelectronic species is the species which contains the equal charge. The isoelectronic species shows the similar chemical properties.

Answer to Problem 42E

The statement “Strontium $\left(\text{Z}=38\right)$ ions, ${\text{Sr}}^{\text{2+}}$, are isoelectronic with bromide ions, ${\text{Br}}^{-}$” is true.

Explanation of Solution

The isoelectronic species are those in which the number of electrons are same.

The electronic configuration of ${\text{Sr}}^{\text{2+}}$ is shown below.

$1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}3d^{10}4s^{2}4p^6$

The electronic configuration of ${\text{Br}}^{-}$ is shown below.

$1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^{2}3d^{10}4p^6$

Since the number of electrons in ${\text{Sr}}^{\text{2+}}$ is $36$ and the number of electrons in ${\text{Br}}^{-}$ are also $36$.

Therefore, ${\text{Sr}}^{\text{2+}}$ and ${\text{Br}}^{-}$ are isoelectronic.

Conclusion

The given statement is true.

Interpretation Introduction

(e)

Interpretation:

Whether the statement “The monoatomic ion formed by selenium $\left(\text{Z}=34\right)$ is expected to be isoelectronic with a noble gas atom” is true or false is to be stated.

Concept introduction:

The ions or atoms which possess the same electron configuration are known as the isoelectronic species. The meaning of isoelectronic species is the species which contains the equal charge. The isoelectronic species shows the similar chemical properties.

Answer to Problem 42E

The statement “The monoatomic ion formed by selenium $\left(\text{Z}=34\right)$ is expected to be isoelectronic with a noble gas atom” is true.

Explanation of Solution

The isoelectronic species are those in which the number of electrons are same.

The atomic number of selenium is $34$. When selenium gains $2$ electrons then it attains a noble gas configuration that is ofkrypton and becomes more stable.

Therefore, the statement “The monoatomic ion formed by selenium $\left(\text{Z}=34\right)$ is expected to be isoelectronic with a noble gas atom” is true.

Conclusion

The given statement is true.

Interpretation Introduction

(f)

Interpretation:

Whether the statement “Most elements in Group $4\text{A}/14$ do not normally form monoatomic ions” is true or false is to be stated.

Concept introduction:

The monoatomic ion is one that is formed by a single atom. In a montoatomic ion, the number of protons and electrons are different. The difference in the number of protons and electrons gives the charge to the atom. When the number of proton is more then the atom attains a positive charge. When the number of electrons is more then the atom acquires a negative charge.

Answer to Problem 42E

The statement “Most elements in Group $4\text{A}/14$ do not normally form monoatomic ions” is true.

Explanation of Solution

The elements of group $4\text{A}/14$ contains $6$ electrons in their valence shell. So, it tries to gain two more electrons in order to complete its octet and get stable. Therefore, it forms a diatomic compound.

So, the statement “Most elements in Group $4\text{A}/14$ do not normally form monoatomic ions” is true.

Conclusion

The given statement is true.

Interpretation Introduction

(g)

Interpretation:

Whether the statement “Multiple bonds can form only between atoms of the same element” is true or false is to be stated.

Concept introduction:

The forces that holds various constituents such as atoms, ions or elements together and forms a chemical compound is known as chemical bonding.

The chemical bonds holds together the atoms in the molecules.

Answer to Problem 42E

The statement “Multiple bonds can form only between atoms of the same element” is false.

Explanation of Solution

The bonds between the different elements can be more than one. The example to this is the molecule of $\text{RCN}$.

Figure 1

The Figure 1 shows $3$ bonds between the atom of carbon and nitrogen.

Therefore, the statement “Multiple bonds can form only between atoms of the same element” is false.

Conclusion

The given statement is false.

Interpretation Introduction

(h)

Interpretation:

Whether the statement “If an atom is triple-bonded to another atom, it may still form a bond with one additional atom” is true or false is to be stated.

Concept introduction:

The forces that hold various constituents such as atoms, ions or elements together and forms a chemical compound is known as chemical bonding.

The chemical bonds hold together the atoms in the molecules.

Answer to Problem 42E

The statement “If an atom is triple-bonded to another atom, it may still form a bond with one additional atom” is true.

Explanation of Solution

In order to complete the octet, the triple bonded atoms can form bond with the other atom. The example to this is the molecule of $\text{HCN}$.

Figure. 2

In Figure 2, the carbon atom is triply bonded with nitrogen atom but still its octet is not complete. Therefore, to complete its octet, it forms a bond with the hydrogen atom.

So, the statement “If an atom is triple-bonded to another atom, it may still form a bond with one additional atom” is true.

Conclusion

The given statement is true.

Interpretation Introduction

(i)

Interpretation:

Whether the statement “An atom that conforms to the octet rule can bond to no more than three other atoms if one bond is a double bond” is true or false is to be stated.

Concept introduction:

The forces that hold various constituents such as atoms, ions or elements together and forms a chemical compound is known as chemical bonding.

The chemical bonds hold together the atoms in the molecules.

Answer to Problem 42E

The statement “An atom that conforms to the octet rule can bond to no more than three other atoms if one bond is a double bond” is true.

Explanation of Solution

When an atom attains eight electrons in its outermost shell then it is known to have a complete octet.

When the atom is bonded with the other atom with a double bond then it can form single bonds with only two other atoms and therefore, its octet will be completed.

So, the statement “An atom that conforms to the octet rule can bond to no more than three other atoms if one bond is a double bond” is true.

Conclusion

The given statement is true.

Interpretation Introduction

(j)

Interpretation:

Whether the statement “Electrons are localized between atoms in a metal” is true or false is to be stated.

Concept introduction:

The substance that has high electrical conductivity and that readily donates electrons in order to attain a positive charge is defined as a metal. Most of the metals react with oxygen to produce oxides.

Answer to Problem 42E

The statement “Electrons are localized between atoms in a metal” is false.

Explanation of Solution

The electrons are present inside the atoms and not between the atoms. So, the localization of electrons between the atom is not possible.

Therefore, the statement “Electrons are localized between atoms in a metal” is false.

Conclusion

The given statement is false.

Interpretation Introduction

(k)

Interpretation:

Whether the statement “Alloys are pure substances” is true or false is to be stated.

Concept introduction:

The fusion of two or more metals that chemically combines together is known as an alloy. The fusion of metal with a non-metal is also possible. An alloy is a homogenous mixture, so, it retains the properties of metal even when it is made up of a non-metal or metalloid.

Answer to Problem 42E

The statement “Alloys are pure substances” is false.

Explanation of Solution

An alloy is formed by a mixture of two or more metals or one metal and other non-metal. So, an alloy can not be pure, rather it is a mixture.

Therefore, the statement “Alloys are pure substances” is false.

Conclusion

The given statement is false.