Who proposed the acid-base theory of ionization?

According to the Arrhenius theory,an acid is a hydrogen-containing compound that produces $..........$ in its aqueous solution.

What are antacids? Explain their role in providing relief from stomach ache.

$A$ substance $X$, which is an oxide of a group $2$ element, is used intensively in the cement industry. This element is present in bones also. On treatment with water, it forms a solution which turns red litmus blue. Identify $X$ and write the chemical reactions involved.

Which of the following statements is true for acids?

Why do $HCl$,$HNO_3$,etc.,show acidic characters in aqueous solutions while solutions of compounds like alcohol and glucose do not show acidic character?