Question

206. Compounds like alcohols and glucose contain hydrogen atoms but are not categorised as acids. Discuss an activity to prove it.

Answer 1

Part 1: Acids

• Acids are substances that generate ${\mathrm{H}}^{+}$ ions in an aqueous solution.
• The release of the H⁺ ion in water determines whether a compound is acidic or non-acidic.
• Alcohols and glucose contain hydrogen atoms but are not considered acids because the hydrogen in them does not separate as easily as the hydrogen in acids.
• When they dissolve in water, they will not separate into hydrogen ions.

Part 2: Activity to prove alcohols and glucose also contain hydrogen but are not categorized as acids are:

(i)Samples of alcohol, glucose, and hydrochloric acid are taken.

(ii) A 100mL beaker is taken with a fork and nails are fixed.

(iii) Cork is placed inside the beaker and nails are connected to two terminals of a 6-volt battery through a bulb and switch.

(iv) Hydrochloric acid is added to the beaker and the current is switched on.

(v) The procedure is repeated for glucose and alcohol too.

(vi) In the case of acid, it is observed that the bulb will glow.

(vii) In the case of alcohol and glucose, it is observed that the bulb does not glow.

• Since ions carry the electric current through the solution, the above conclusion can be made.
• Acid ionizes to give ${\mathrm{H}}^{+}$ ions in an aqueous medium but glucose and alcohol do not furnish ${\mathrm{H}}^{+}$ ions even though they contain hydrogen atoms.