Which of the following substances is an antacid?

Equal lengths of magnesium ribbons are taken in test tubes $A$ and $B$. Hydrochloric acid $(HCl)$ is added to test tube $A$,while acetic acid $(CH_3COOH)$ is added to test tube $B$. The amount and concentration taken for both the acids are the same. In which test tube will the fizzing occur more vigorously and why?

What precaution must be taken while diluting a concentrated acid?

Do basic solutions also have $H^+_{(aq)}$ ions? If yes,then why are these basic?

Compounds such as alcohols and glucose also contain hydrogen but are not categorized as acids. Describe an activity to prove that they do not show acidic character.

Tap water conducts electricity,whereas distilled water does not. Why?