Chapter 2, Problem 55QAP

Interpretation Introduction

(a)

Interpretation:

To write the chemical formula of methane.

Concept introduction:

Methane is first member of Alkane family that has only 1 carbon atom (‘meth’ prefix used for 1 carbon).

General molecular formula for alkanes:

${\text{C}}_{\text{n}}{\text{H}}_{\left(\text{2n+2}\right)}$

Where n represents the number of carbon atoms.

Answer to Problem 55QAP

Chemical formula of methane is CH₄.

Explanation of Solution

Methane is a member of Alkane family that has only 1 carbon atom and general formula for molecular formula of Alkane is:

${\text{C}}_{\text{n}}{\text{H}}_{\left(\text{2n+2}\right)}$

Where n represents the number of carbon atoms.

Therefore,

Molecular formula of methane:

$\begin{array}{l}{\text{ C}}_{\text{n}}{\text{H}}_{\left(\text{2n+1}\right)}\\ \text{putting}\text{value}\text{of}\text{n =1,}\text{we}\text{get:}\\ \Rightarrow {\text{C}}_{\text{1}}{\text{H}}_{\left(\text{2(1)+1}\right)}\\ \Rightarrow {\text{C}}_{\text{1}}{\text{H}}_{\text{4}}\to {\text{CH}}_{\text{4}}\end{array}$

Interpretation Introduction

(b)

Interpretation:

To write the chemical formula of carbon tetraiodide.

Concept introduction:

Naming format for covalent binary compounds:

$\left(\begin{array}{l}\text{prefix}\text{for}\\ \text{least}\text{electronegative}\\ \text{atom}\end{array}\right)\left(\begin{array}{l}\text{name}\text{of}\\ \text{least}\text{electronegative}\\ \text{atom}\end{array}\right)\left(\begin{array}{l}\text{prefix}\text{for}\\ \text{most}\text{electronegative}\\ \text{atom}\end{array}\right)\left(\begin{array}{l}\text{name}\text{of}\\ \text{most}\text{electronegative}\\ \text{atom}\text{ending}\text{with}\text{-ide}\end{array}\right)$

Prefixes are used as mono, di, tri, tetra, penta, hexa and so on for the number of each element present in a molecule. Generally, we don’t use mono prefix while writing the name of covalent compoundsas by convection if no prefix is used, then it means we have 1 atom of that respective element.

Answer to Problem 55QAP

Formula of carbon tetraiodide is CI₄.

Explanation of Solution

Here we have:

Chemical name of molecule = Carbon tetraiodide

In this chemical compound:

Least electronegative atom = Carbon and its symbol is C.

Most electronegative atom = Iodine and its symbol is I.

Prefix used for least electronegative atom = “none” that means only 1 carbon atom.

Prefix used for most electronegative atom = “tetra” that means only 4 Iodine atoms.

Thus,

Molecular formula for carbon tetraiodide = CI₄

Interpretation Introduction

(c)

Interpretation:

To write the chemical formula of hydrogen peroxide.

Concept introduction:

Hydrogen peroxide is also known as dihydrogen dioxide.

Naming format for covalent binary compounds:

$\left(\begin{array}{l}\text{prefix}\text{for}\\ \text{least}\text{electronegative}\\ \text{atom}\end{array}\right)\left(\begin{array}{l}\text{name}\text{of}\\ \text{least}\text{electronegative}\\ \text{atom}\end{array}\right)\left(\begin{array}{l}\text{prefix}\text{for}\\ \text{most}\text{electronegative}\\ \text{atom}\end{array}\right)\left(\begin{array}{l}\text{name}\text{of}\\ \text{most}\text{electronegative}\\ \text{atom}\text{ending}\text{with}\text{-ide}\end{array}\right)$

Prefixes are used as mono, di, tri, tetra, penta, hexa and so on for the number of each element present in a molecule. Generally, we don’t use mono prefix while writing the name of covalent compounds as by convection if no prefix is used, then it means we have 1 atom of that respective element.

Answer to Problem 55QAP

Formula of hydrogen peroxide is H₂ O₂.

Explanation of Solution

Here we have:

Chemical name of molecule = Hydrogen peroxide

Its other name is dihydrogen dioxide.

In this chemical compound:

Least electronegative atom = Hydrogen and its symbol is H.

Most electronegative atom = Oxygen and its symbol is O.

Prefix used for least electronegative atom = “di” that means only 2 atoms.

Prefix used for most electronegative atom = “di” that means only 2 atoms.

Thus,

Molecular formula for dihydrogen dioxide = H₂ O₂.

Interpretation Introduction

(d)

Interpretation:

To write the chemical formula of nitrogen oxide.

Concept introduction:

Naming format for covalent binary compounds:

$\left(\begin{array}{l}\text{prefix}\text{for}\\ \text{least}\text{electronegative}\\ \text{atom}\end{array}\right)\left(\begin{array}{l}\text{name}\text{of}\\ \text{least}\text{electronegative}\\ \text{atom}\end{array}\right)\left(\begin{array}{l}\text{prefix}\text{for}\\ \text{most}\text{electronegative}\\ \text{atom}\end{array}\right)\left(\begin{array}{l}\text{name}\text{of}\\ \text{most}\text{electronegative}\\ \text{atom}\text{ending}\text{with}\text{-ide}\end{array}\right)$

Prefixes are used as mono, di, tri, tetra, penta, hexa and so on for the number of each element present in a molecule. Generally, we don’t use mono prefix while writing the name of covalent compounds as by convection if no prefix is used, then it means we have 1 atom of that respective element.

Answer to Problem 55QAP

Formula of nitrogen oxide is NO.

Explanation of Solution

Here we have:

Chemical name of molecule = Nitrogen oxide

In this chemical compound:

Least electronegative atom = Nitrogen and its symbol is N.

Most electronegative atom = Oxygen and its symbol is O.

Prefix used for least electronegative atom = “none” that means only 1 nitrogen atom.

Prefix used for most electronegative atom = “none” that means only 1 oxygen atom.

Thus,

Molecular formula for nitrogen oxide = NO

Interpretation Introduction

(e)

Interpretation:

To write the chemical formula of silicon dioxide.

Concept introduction:

Naming format for covalent binary compounds:

$\left(\begin{array}{l}\text{prefix}\text{for}\\ \text{least}\text{electronegative}\\ \text{atom}\end{array}\right)\left(\begin{array}{l}\text{name}\text{of}\\ \text{least}\text{electronegative}\\ \text{atom}\end{array}\right)\left(\begin{array}{l}\text{prefix}\text{for}\\ \text{most}\text{electronegative}\\ \text{atom}\end{array}\right)\left(\begin{array}{l}\text{name}\text{of}\\ \text{most}\text{electronegative}\\ \text{atom}\text{ending}\text{with}\text{-ide}\end{array}\right)$

Prefixes are used as mono, di, tri, tetra, penta, hexa and so on for the number of each element present in a molecule. Generally, we don’t use mono prefix while writing the name of covalent compounds as by convection if no prefix is used, then it means we have 1 atom of that respective element.

Answer to Problem 55QAP

Formula of silicondioxide is SiO₂.

Explanation of Solution

Here we have:

Chemical name of molecule = Silicon dioxide

In this chemical compound:

Least electronegative atom = Silicon and its symbol is Si.

Most electronegative atom = Oxygen and its symbol is O.

Prefix used for least electronegative atom = “none” that means only 1 silicon atom.

Prefix used for most electronegative atom = “di” that means 2 oxygen atoms.

Thus,

Molecular formula for silicon dioxide = SiO₂