Railway Science (Chemistry-Organic Chemistry) (Part-III)

Consumption of ethanol leads to diseases like fatty liver, alcoholic hepatitis, cirrhosis, High blood pressure, heart disease, stroke, liver disease, and digestive problems. Other compounds and formula: Methanol - CH₃OH, Butanol - C₄H₁₀O, Propanol - C₃H₈O.

Alkanes (CₙH₂ₙ₊₂) are saturated compounds because they have a single bond between Carbon and Hydrogen. Example - Methane (CH₄), ethane (C₂H₆). Alkynes (CₙH₂ₙ₋₂) are hydrocarbons that contain carbon -carbon triple bonds. Example - Ethyne and propyne. Alkene (CₙH₂ₙ) are hydrocarbons that possess at least one carbon-carbon double bond. Example - Ethene - C₂H₄  ,propene - C₃H₆ .

The molecular mass of a substance is the sum of atomic masses of all the atoms in a molecule of the substance. Molecular mass of each successive member in a homologous series differs by molecular mass of 14u by the preceding member. General formula of a homologous series of hydrocarbons is CₙH₂ₙ₊₂. Carbon (Atomic Mass- 12), Hydrogen (1). The difference in molecular mass of C₅H₁₂ (pentane) - C₃H₈ (propane) = (12 × 5 + 1 × 12) - (12 × 3 + 1 × 8) = 28 u.

Molecular mass of ethanol (C₂H₅OH) = 2(12) + 5(1) + 16 + 1 = 46 g/mol. Molecular mass of methanol (CH₃OH) = 12 + 3(1) + 16 + 1 = 32 g/mol.
The difference in molecular mass between ethyl alcohol and methyl alcohol is = 46 - 32 = 14 g/mol.

homologous series of alkanes : CH₄ , C₂H₆ , C₃H₈ , C₄H₁₀ and so on...
if we see in terms of molecular mass, the difference is ,
molecular mass of [(C₂H₆) - (CH₄)]
= (12 × 2 + 1 × 6) - (12 × 1 + 1 × 4)
= 30 - 16 = 14 u