Methane to hexane

The idea

The saturated carbon chains with 1 to 6 carbon atoms are methane (CH4), ethane (C2H6), propane (C3H8), butane (C4H10), pentane (C5H12) and hexane (C6H14).

A growing chain

Methane has one carbon atom and four hydrogen atoms. Add carbon atoms one at a time to make a chain, and fill every valency with hydrogen.

Look at the formulae CH₄ and C₂H₆. What happens to the number of hydrogen atoms as the chain grows by one carbon atom?

• It stays the same
• It goes up
• It goes down

Build the chain

Use the + and − buttons to change the number of carbon atoms. Watch the name and the formula.

Six saturated chains

Each chain has only single bonds between its carbon atoms, so these are saturated compounds. Their names start with meth, eth, prop, but, pent and hex for 1 to 6 carbon atoms.

The saturated carbon chains with 1 to 6 carbon atoms are methane (CH₄), ethane (C₂H₆), propane (C₃H₈), butane (C₄H₁₀), pentane (C₅H₁₂) and hexane (C₆H₁₄).

• Carbon atoms | Name | Formula
• 1 | methane | CH₄
• 2 | ethane | C₂H₆
• 3 | propane | C₃H₈
• 4 | butane | C₄H₁₀
• 5 | pentane | C₅H₁₂
• 6 | hexane | C₆H₁₄

Notes

The saturated carbon chains with 1 to 6 carbon atoms are methane (CH₄), ethane (C₂H₆), propane (C₃H₈), butane (C₄H₁₀), pentane (C₅H₁₂) and hexane (C₆H₁₄).

Check yourself

What is the name of the saturated chain with 3 carbon atoms, C₃H₈?

How many hydrogen atoms are there in a molecule of butane, C₄H₁₀?

Answer: 10

The formula C₄H₁₀ has 10 hydrogen atoms.

How many carbon atoms are there in a molecule of pentane, C₅H₁₂?

Answer: 5

The formula C₅H₁₂ has 5 carbon atoms.

Which formula belongs to hexane?

• Butane. Butane has 4 carbon atoms and the formula C₄H₁₀.
• Propane — correct. Yes!
• Ethane. Ethane has 2 carbon atoms and the formula C₂H₆.
• C₆H₁₂. C₆H₁₂ is the formula of cyclohexane, which has a ring. Hexane, the chain, is C₆H₁₄.
• C₅H₁₂. C₅H₁₂ is pentane, which has 5 carbon atoms.
• C₆H₁₄ — correct. Yes!