How do you test for the presence of ethanoic acid?

You can test for the presence of ethanoic acid by using sodium carbonate or sodium hydrogen carbonate.

Ethanoic acid, also known as acetic acid, is a weak organic acid that can be identified using a simple chemical reaction with sodium carbonate (Na2CO3) or sodium hydrogen carbonate (NaHCO3). When ethanoic acid reacts with either of these substances, it produces carbon dioxide gas, water, and a salt. The release of carbon dioxide gas is a key indicator of the presence of ethanoic acid.

To perform the test, you would add a few drops of the substance suspected to contain ethanoic acid to a small amount of sodium carbonate or sodium hydrogen carbonate. If the substance contains ethanoic acid, the reaction will produce bubbles of carbon dioxide gas. This is a result of the acid reacting with the carbonate or hydrogen carbonate to produce a salt, water, and carbon dioxide.

The chemical equation for the reaction with sodium carbonate is:

CH3COOH + Na2CO3 → 2CH3COONa + H2O + CO2

And for the reaction with sodium hydrogen carbonate, the equation is:

CH3COOH + NaHCO3 → CH3COONa + H2O + CO2

In both reactions, the production of carbon dioxide gas is the key indicator of the presence of ethanoic acid. This is a simple and effective test that can be performed in a laboratory setting. It's important to remember that safety precautions should be taken when handling these chemicals, including wearing protective eyewear and gloves.