Introduction to Organic Chemistry: The Building Blocks

Alkanes are the simplest organic compounds you'll encounter, and they're everywhere around you - from the gas in your cooker (methane) to the fuel in cars (octane). These are called saturated hydrocarbons because they contain only hydrogen and carbon atoms connected by single bonds.

The beauty of alkanes lies in their predictable pattern. Every straight-chain alkane follows the formula CₙH₂ₙ₊₂, where 'n' is the number of carbon atoms. So if you've got 4 carbons like in butane, you'll have (2×4)+2 = 10 hydrogens, giving you C₄H₁₀.

You'll need to memorise the first ten alkanes, from methane (CH₄) right up to decane (C₁₀H₂₂). The names might seem random, but they follow Greek number patterns - 'pent' means five, 'hex' means six, and so on. Each carbon atom forms four bonds at a bond angle of 109.5°, creating a tetrahedral shape that's crucial for understanding molecular behaviour.

Quick Tip: When drawing structural formulae, remember that skeletal structures only show carbon-carbon bonds as lines - all the hydrogen atoms are implied!

Isomers are molecules with the same molecular formula but different structures. Butane (C₄H₁₀) can be arranged as a straight chain or with a branch, creating two completely different compounds with identical formulas but different properties.

Beyond alkanes, you'll encounter alkenes $with double C=C bonds$, alkynes (with triple C≡C bonds), and arenes (containing benzene rings). These unsaturated hydrocarbons are more reactive than alkanes because their multiple bonds can break and form new connections.