Question

Why alkane is saturated?

Answer 1

$\huge\colorbox{cyan}{Answer:-}$

$\huge\mathfrak\pink{==>}$Alkanes are known as saturated molecules because other atoms cannot add to them. In other words, the carbon atoms are bonded to as many other atoms as they can.

$\huge\mathfrak\pink{==>}$Alkanes are saturated hydrocarbons. This means that their carbon atoms are joined to each other by single bonds. This makes them relatively unreactive, apart from their reaction with oxygen in the air - which we call burning or combustion. Like other homologous series, the alkanes show isomerism.

$\huge\colorbox{cyan}{Explanation:-}$

$\huge\mathfrak\pink{==>}$Alkenes and alkynes are called unsaturated compounds because the carbon atoms do not have as many hydrogen atoms as they possibly could. ... It is saturated because every carbon holds as many hydrogen atoms as possible.

$\huge\mathfrak\pink{==>}$We begin our study of organic chemistry with the hydrocarbons, the simplest organic compounds, which are composed of carbon and hydrogen atoms only. As we noted, there are several different kinds of hydrocarbons. They are distinguished by the types of bonding between carbon atoms and the properties that result from that bonding. Hydrocarbons with only carbon-to-carbon single bonds (C–C) and existing as a continuous chain of carbon atoms also bonded to hydrogen atoms are called alkanes (or saturated hydrocarbons). Saturated, in this case, means that each carbon atom is bonded to four other atoms (hydrogen or carbon)—the most possible; there are no double or triple bonds in the molecules.

The word saturated has the same meaning for hydrocarbons as it does for the dietary fats and oils: the molecule has no carbon-to-carbon double bonds (C=C).

We previously introduced the three simplest alkanes—methane (CH4), ethane (C2H6), and propane (C3H8) and they are shown again in Figure 21.4.121.4.1 .

12.1.jpg

Figure 21.4.121.4.1 : The Three Simplest Alkanes

The flat representations shown do not accurately portray bond angles or molecular geometry. Methane has a tetrahedral shape that chemists often portray with wedges indicating bonds coming out toward you and dashed lines indicating bonds that go back away from you. An ordinary solid line indicates a bond in the plane of the page. Recall that the VSEPR theory correctly predicts a tetrahedral shape for the methane molecule (Figure 21.4.221.4.2 ).

12.2.jpg

Figure 21.4.221.4.2 : The Tetrahedral Methane Molecule

Methane (CH4), ethane (C2H6), and propane (C3H8) are the beginning of a series of compounds in which any two members in a sequence differ by one carbon atom and two hydrogen atoms—namely, a CH2 unit. The first 10 members of this series are given in Table 21.4.121.4.1 .

Table 21.4.121.4.1 : The First 10 Straight-Chain Alkanes

methane

CH4

CH4

—

ethane

C2H6

CH3CH3

—

propane

C3H8

CH3CH2CH3

—

butane

C4H10

CH3CH2CH2CH3

2

pentane

C5H12

CH3CH2CH2CH2CH3

3

hexane

C6H14

CH3CH2CH2CH2CH2CH3

5

heptane

C7H16

CH3CH2CH2CH2CH2CH2CH3

9

octane

C8H18

CH3CH2CH2CH2CH2CH2CH2CH3

18