C₆H₁₄ is the only Alkane in given compounds.
The General Formula for Alkanes is as follow;
Cₓ H₂ₓ ₊ ₂
where;
x = whole number
It means in alkanes for every x number of carbon atoms we have 2x + 2 number of hydrogen atoms. Let's apply this formula on given compounds.
CH₂O:
As there is one carbon atom in this compound hence, the number of hydrogen atoms present for one carbon atom in alkane must be equal to,
H₂₍₁₎ ₊ ₂
H₂ ₊ ₂
H₄
Hence, this compound is not alkane because it contains only two hydrogen atoms.
C₆H₁₄:
As there are six carbon atoms in this compound hence, the number of hydrogen atoms present for six carbon atoms in alkane must be equal to,
H₂₍₆₎ ₊ ₂
H₁₂ ₊ ₂
H₁₄
Hence, this compound is alkane because it contains fourteen hydrogen atoms.
C₃H₄:
As there are three carbon atoms in this compound hence, the number of hydrogen atoms present for three carbon atoms in alkane must be equal to,
H₂₍₃₎ ₊ ₂
H₆ ₊ ₂
H₈
Hence, this compound is not alkane because it contains only four hydrogen atoms.
