Which of the following is a weak acid?

Which of the following substances will not give carbon dioxide on treatment with dilute acid?

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.

Identify the compound $X$ on the basis of the reactions given below. Also,write the name and chemical formulae of $A$,$B$ and $C$.

What happens when nitric acid is added to an egg shell?

If the approximate $pH$ of a solution is $7,$ what will be the colour of $pH$ paper when dipped into that solution?