Write the molecular formula, the semideveloped formula and name the linear alkanes of 20, 30, 40, 50 and 100 carbons.

Solution

♣ The 20-carbon alkane is called Eicos ano , its molecular formula is C₂₀H₄₂ , (all alkanes respond to the formula C_nH_2n+2 ). In the semi-developed formula, the methyls at the ends are written and the number of CH₂ that the alkane has, CH₃(CH₂)₁₈CH_3, is indicated in parentheses.

♣ The alkane with 30 carbons is called Triacontano . Molecular formula: C₃₀H₆₂ . Semi-developed formula: CH₃(CH₂)₂₈CH ₃ .

♣ With 40 carbons : Tetracontano . Molecular formula: C₄₀H₈₂ . Semi-developed formula: CH₃(CH₂)₃₈CH₃

♣ With 50 carbons: Pentacount year . Molecular formula: C₅₀H₁₀₂ . Semi-developed formula: CH₃(CH₂)₄₈CH₃

♣ The alkane of 100 carbons is called Hectane