Ethanol Reactions: Sodium & Esterification

Why it matters

Sodium metal hisses and vanishes in ethanol, releasing a gas that pops with a flame. Add ethanoic (acetic) acid with a little concentrated sulphuric acid and warm it, and the sharp smell fades into a sweet, fruity aroma.

The idea in plain words

Observe the displacement: sodium replaces hydrogen in the alcohol structure.

Predict first

What gas is released when sodium reacts with ethanol?

The reaction displaces hydrogen from the hydroxyl group, producing sodium ethoxide and hydrogen gas.

• Hydrogen — correct
• Oxygen
• Carbon dioxide
• Ethane

What you do

First, drop sodium into ethanol and test the gas with a burning splinter. Then, mix ethanol with acetic acid, add concentrated sulfuric acid, and warm the mixture to smell the product.

Check yourself

How do you confirm the gas evolved in the sodium-ethanol reaction?

Hydrogen gas burns with a characteristic 'pop' sound when tested with a burning splinter.

What are the conditions required for ethanol to react with acetic acid to form an ester?

Esterification requires concentrated H₂SO₄ as a catalyst and heat to proceed efficiently.

Which equation correctly represents the reaction between ethanol and sodium?

The balanced equation shows two moles of ethanol reacting with two moles of sodium to produce two moles of sodium ethoxide and one mole of hydrogen gas.

• It turns lime water milky
• It burns with a pop sound — correct
• It relights a glowing splinter
• It has a rotten egg smell
• Room temperature and no catalyst
• Heating with concentrated sulfuric acid — correct
• Cooling with dilute hydrochloric acid
• Exposure to sunlight only
• C₂H₅OH + Na → C₂H₅ONa + H₂
• 2C₂H₅OH + 2Na → 2C₂H₅ONa + H₂ — correct
• C₂H₅OH + Na → C₂H₅Na + OH
• 2C₂H₅OH + Na → 2C₂H₅ONa + H₂