Hydrocarbons — Flashcards

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The general formula of alkanes is CₙH₂ₙ₊₂. For example, methane (CH₄) where n=1: C₁H₄.

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CH₃COONa + NaOH → CH₄ + Na₂CO₃ This reaction occurs on heating sodium acetate with soda lime (NaOH + CaO). It is a decarboxylation reaction where an alkane with one less carbon is formed.

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The Wurtz reaction involves two alkyl halides reacting with sodium in dry ether to form a higher alkane. Example: 2CH₃Br + 2Na → CH₃–CH₃ + 2NaBr This method is useful for preparing symmetrical alkanes…

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Branching reduces the surface area of alkane molecules, which weakens the van der Waals forces between them. Weaker intermolecular forces require less energy to overcome, hence lower boiling point. Ex…

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CH₃–CH₃ + Cl₂ → CH₃–CH₂Cl + HCl Further substitution gives CH₃–CHCl₂, CHCl₂–CHCl₂, etc. This is a free radical substitution reaction initiated by UV light, proceeding via chain mechanism: initiation, …

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Given: CH₄ + 2O₂ → CO₂ + 2H₂O + 890 kJ/mol So, 1 mole of methane releases 890 kJ of heat. Answer: 890 kJ…

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Alkanes are called paraffins because they have little affinity (low reactivity) towards common reagents due to strong C–C and C–H sigma bonds and non-polar nature. 'Parum' means little, 'affins' means…

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CH₃–CH=CH₂ + HBr → CH₃–CH₂–CH₂Br (1-bromopropane) This follows Anti-Markovnikov's rule (Peroxide effect), where Br adds to terminal carbon due to free radical mechanism.