State reason for the following:

(i) Dry $\text{HCl}$ gas does not change the colour of the dry blue litmus paper.

(ii) Alcohol and glucose also contain hydrogen, but do not conduct electricity.

(iii) Concentration of $\text{H}_3\text{O}^+$ ion is affected when a solution of an acid is diluted.

(i) Dry $HCl$ gas does not change the colour of dry blue litmus paper because the separation of $H^+$ ions from $HCl$ molecules can only occur in the presence of water. Since both the gas and the litmus paper are dry, no hydronium ions ($H_3O^+$) are formed to exhibit acidic properties.

(ii) Alcohol and glucose contain hydrogen but do not conduct electricity because they do not dissociate into free ions (such as $H^+$ ions) when dissolved in water. Electric current in a solution is carried by free-moving ions, which are absent in glucose and alcohol solutions.

(iii) Concentration of $H_3O^+$ ions is affected on dilution because mixing an acid with water increases the total volume of the solution. This results in a decrease in the number of hydronium ions ($H_3O^+$) per unit volume.