Year 9 Science · Unit 2 · Lesson 13

Naming and Representing Alkanes

Foundation Worksheet

Name

Date

Class

Learning Goals

Recall the IUPAC prefixes for alkanes with 1–10 carbon atoms and apply the "-ane" suffix.
Distinguish between molecular, condensed, and displayed structural formulas.
Convert between the name, molecular formula, and condensed structural formula of a simple alkane.

Warm Up

Match each term to its definition

Draw a line connecting each term on the left to its correct definition on the right. Or write the matching letter next to each term.

Term	Your answer	Definition
Methane		A. A system developed by chemists worldwide so that every compound has one agreed, unambiguous name.
Propane		B. A formula that shows every atom and every bond drawn as a line between atoms.
Hexane		C. The simplest alkane; one carbon atom bonded to four hydrogen atoms (CH₄).
Molecular formula		D. An alkane with three carbon atoms and the condensed formula CH₃–CH₂–CH₃.
Structural formula		E. A formula showing only the number and type of atoms in one molecule (e.g. C₃H₈).
IUPAC naming		F. An alkane with six carbon atoms; its name uses the prefix "hex-".

Odd one out

Circle the item that does not belong in each group. Then explain why it doesn't fit.

#	Group	Your answer (odd one + reason)
1	Methane Ethane Propane Ethanol
2	CH₄ C₂H₆ C₃H₈ C₃H₇OH
3	meth- eth- prop- benz-

1. The molecular formula C₅H₁₂ belongs to an alkane. State its IUPAC name and write its condensed structural formula.

Recall 2 marks

2. Explain why chemists worldwide agreed to use the IUPAC naming system instead of continuing to use common names for organic compounds.

Recall 2 marks

Wrap Up

In one sentence, what was the main idea of this lesson?