Compound with the general formula CnH$_{2n+2}$ belong to the_______ group

Step 1: Analyze the question We need the homologous series with general formula CₙH₂ₙ₊₂.

Step 2: Concept Hydrocarbon general formulas:

• Alkanes: CₙH₂ₙ₊₂ (saturated, only single bonds)
• Alkenes: CₙH₂ₙ (one C=C double bond)
• Alkynes: CₙH₂ₙ₋₂ (one C≡C triple bond)

Alkanal (aldehydes) and alkanoates (esters) contain oxygen, so they cannot be described by a formula with only C and H.

Step 3: Solution Test with n = 1: CH₄ (methane). n = 2: C₂H₆ (ethane). n = 3: C₃H₈ (propane). These are all alkanes, and each fits CₙH₂ₙ₊₂, with every carbon fully bonded by single bonds.

Step 4: Answer The compounds belong to the alkane group, which is option B.

Tip: Remember "the alkane has the most hydrogens": 2n+2 for alkanes, 2n for alkenes, 2n−2 for alkynes. Each double or triple bond removes 2 hydrogens from the formula.