Name and draw the displayed formulae of: (a) methane and ethane (b) ethene (c) ethanol (d) ethanoic acid (e) the products of the reactions stated in sections 11.4-11.7

Objective: Learn how to name and draw the structures of common simple organic molecules and predict the products of key reactions (sections 11.4‑11.7).

Methane – The simplest hydrocarbon: \$CH_4\$

Structural view: \$CH3-CH3\$ (but for methane it's just one carbon with four H atoms).

Ethane – Two carbons single‑bonded: \$C2H6\$

Structural view: \$CH3-CH3\$

🔹 Analogy: Think of carbon atoms as Lego bricks. Methane is a single brick with four Lego studs (hydrogens). Ethane is two bricks connected by a single Lego peg.

Ethene (Ethylene) – An alkene with a double bond: \$C2H4\$

Structural view: \$CH2=CH2\$

🧪 Why double bonds matter: The double bond gives ethene its reactivity – it can add molecules across the bond like a handshake.

Ethanol (Ethyl alcohol) – An alcohol: \$CH3CH2OH\$

Structural view: \$CH3-CH2-OH\$

🍹 Fun fact: Ethanol is the alcohol found in drinks – but remember, it’s also used in labs and as a fuel.

Ethanoic Acid (Acetic acid) – A carboxylic acid: \$CH_3COOH\$

Structural view: \$CH_3-COOH\$

🧪 Why the name matters: “Acetic” comes from the Latin acetum (vinegar). The COOH group is the key functional group that defines acids.

11.4 – Addition of \$H_2\$ to Alkenes

\$CH2=CH2 + H2 \;\longrightarrow\; CH3-CH_3\$

🔹 Takeaway: Adding hydrogen “fills” the double bond, turning an alkene into an alkane.

11.5 – Halogenation of Alkanes

\$CH3-CH3 + Br2 \;\longrightarrow\; CH3-CH_2-Br + HBr\$

🔹 Tip: The product is a haloalkane (bromoethane). Remember the “halo” prefix!

11.6 – Combustion of Alkanes

\$CH3-CH3 + 2O2 \;\longrightarrow\; 2CO2 + 2H_2O\$

🔥 Why it matters: Combustion releases energy – that’s why fuels burn.

11.7 – Oxidation of Alcohols

\$CH3-CH2-OH + [O] \;\longrightarrow\; CH_3-COOH\$

🔬 Key point: Primary alcohols oxidise to aldehydes and then to carboxylic acids (here, ethanol → ethanoic acid).

• 🔑 Remember the suffixes: –ane (alkanes), –ene (alkenes), –ol (alcohols), –oic acid (carboxylic acids).
• 🧠 Practice naming: Write the formula, then the name. Reverse it to check.
• 📚 Use the “C‑rule”: Count the longest chain of carbons first; then add prefixes for branches.
• 💡 Reaction predictions: Know the functional group; the product often keeps the same skeleton but changes the group.
• 📝 Exam strategy: When asked to draw a structure, start with the carbon skeleton, then add hydrogens and functional groups.