State that the bonding in alkanes is single covalent and that alkanes are saturated hydrocarbons

Bonding in Alkanes

Alkanes are built from single covalent bonds only.

Each bond is like a simple handshake between two atoms:

\$C-C\$ – a single line between two carbon atoms

\$C-H\$ – a single line between carbon and hydrogen

Because there are no double or triple bonds, the structure is very stable and “saturated.”

What Makes Alkanes Saturated?

“Saturated” means every carbon atom has the maximum number of hydrogen atoms it can hold, using only single bonds.

For a molecule with \$n\$ carbon atoms, the general formula is:

\$CnH{2n+2}\$

So:

• \$n=1\$: \$CH_4\$ (methane)
• \$n=2\$: \$C2H6\$ (ethane)
• \$n=3\$: \$C3H8\$ (propane)

Each carbon forms four single bonds, either with other carbons or with hydrogens.

Common Alkanes You’ll See Around You

• 🛢️ Gasoline – a mixture of many alkanes (C₄–C₁₂)
• 🧴 Petroleum jelly – long-chain alkanes (C₂₀–C₃₀)
• 🧪 Propane – used in BBQ grills (C₃H₈)
• 🛠️ Octane – component of gasoline (C₈H₁₈)

Exam Tips 📚

1. Remember: All bonds are single → no double/triple bonds in alkanes.
2. Use the formula \$CnH{2n+2}\$ to check if a given compound is an alkane.
3. When drawing structures, start by placing the carbon chain, then add hydrogens to satisfy four bonds per carbon.
4. Look out for “saturated” in the question – it’s a hint that the compound is an alkane.

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