Write true or false for the following statements:
Care must be taken while mixing concentrated nitric acid or sulphuric acid with water. The water must always be added slowly to the acid with constant stirring.

Which of the following is(are) true when $HCl(g)$ is passed through water?
$(i)$ It does not ionise in the solution as it is a covalent compound.
$(ii)$ It ionises in the solution.
$(iii)$ It gives both hydrogen and hydroxyl ion in the solution.
$(iv)$ It forms hydronium ion in the solution due to the combination of hydrogen ion with water molecule.

To protect against tooth decay,we are advised to brush our teeth regularly. The nature of the toothpaste commonly used is:

Why does dry $HCl$ gas not change the colour of the dry litmus paper?

Who proposed the acid-base theory of ionization?

What are solutions that conduct electricity called?