Viva Voce: Properties of Acetic Acid | Lab Manuals for Class 10 PDF Download

Q.1. How will you test that the liberated gas is carbon dioxide?

Carbon dioxide gas turns lime water milky and,the milkiness disappears if excess of CO₂ is passed through the solution.

Q.2. Where do you find the use of ethanoic acid in day-to-day food products?

Ethanoic acid is the main constituent of vinegar which is used as a preservative.

Q.3. When Shweta smells acetic acid, she observes that acid smells like vinegar which is used for preserving pickles. Why does she found the odour of both substances to be similar?

Vinegar is 5-8% aqueous solution of acetic acid. Hence, both substances have; acetic acid as a common constituent. Thus, both have same odour.

Q.4. Blue and red litmus papers were dipped separately in dilute-acetic acid. What colour would you observe on the litmus papers?

Dilute acetic acid turns blue litmus red but does not show any change/effect on red litmus paper.

Q.5. Is acetic acid an inorganic acid?

No, acetic acid is an organic acid.

Q.6. What is glacial acetic acid?

Pure (100%) ethanoic acid is called glacial acetic acid.

Q.7. A student add blue litmus solution to a solution of acetic acid, it turns red. What change will be observed when a few drops of dil. HCl are added to it?

The colour of mixture will not change, i.e. it remains red.

Q.8. A student added acetic acid to a unknown solid A which was already kept in a test tube. A colourless and odourless gas B was evolved. The gas was passed through lime water which turned milky. Identify A and B.

Solid A is sodium carbonate or sodium bicarbonate, and gas B is carbon dioxide.

Q.9. A salt X is formed and a gas is evolved when ethanoic acid reacts with sodium hydrogen carbonate. Name the salt X and the gas evolved.

Q.10. Which salt of carboxylic acid is commonly used as food preservative?

Sodium benzoate is used as a food preservative.

Q.11. When a white powder was mixed with acetic acid, a colourless and odourless gas was produced which turns lime water milky. What is this white powder?

White powder is sodium hydrogen carbonate (NaHCO₃) which evolve CO₂ gas, turns time water milky

Q.12. Acetic acid was added to small pieces of marble and the gas evolved was tested with a burning splinter. What do you observe?

CO₂ gas is evolved and when it is tested with a burning splinter then the gas does not burn but extinguishes the flame.

Q.13. What is the common name of ethanoic acid as sold in the market in the form of its dilute solution?

A dilute solution of ethanoic acid is vinegar.

Q.14. How will you show that ethanoic acid is acidic in nature?

The acidic nature of ethanoic acid can be shown by using blue litmus paper. Dip the blue litmus paper in ethanoic acid. If it turns red, it means ethanoic acid is acidic in nature.

Q.15. Which gas is evolved when ethanoic acid reacts with sodium hydrogen carbonate?

Carbon dioxide (CO₂) gas is evolved when ethanoic acid reacts with sodium hydrogen carbonate.
CH₃COOH (aq) + NaHCO₃(s) ——–> CH₃COONa (aq) + H₂O (l) + CO₂(g)