Write the condensed formula of a linear alkane, whose molecular formula is C₂₀H₄₂ .

SOLUTION:
Linear alkanes can be written in condensed form using the following formula: CH₃(CH₂)_nCH₃ , where n is the number of CH₂ the molecule has. The molecular formula of the problem has 20 carbons, two of them are for methyls, therefore, the condensed formula will have 18 CH₂ .

Condensed formula: CH₃(CH₂)₁₈CH₃