Question

What do you observe when you drop a few drops of acetic acid to a test tube containing:

a) Phenolphthalein c) distilled water
b) Universal indicator d) sodium hydrogen carbonate

Answer 1

Answer:

Explanation:

i) Acetic acid will remain colourless in phenolphthalein.

ii) Acetic acid will dissolve in distilled water forming a clear solution.

iii) Universal indicator gives orange colour with acetic acid.

iv) Sodium hydrogen carbonate will give brisk effervescence due to the formation of CO2 gas.

Answer 2

Answer:

Acetic acid is a weak acid, following changes are observed --

(i) Phenolphthalein → no change/remains colorless

(ii) Distilled water → acetic acid dissolves in distilled water.

(iii) Universal indicator → turns orange

(iv) When added to Sodium hydrogen carbonate powder evolution of colorless, odorless gas (carbon dioxide) with brisk effervescence takes place.

CH3COOH(aq) + NaHCO3. CH3COOHNa (aq) +H2O(1) + CO2(gas)