Write true or false for the following statement:
The separation of $H^+$ ions from $HCl$ molecules can occur in the absence of water.

If $1$ mole of glucose is dissolved in $500 \; mL$ of glucose solution,what is the molarity of the solution (in $; M$)?

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.

Three acidic solutions $A, B$ and $C$ have $pH = 0, 3$ and $5$ respectively.
$(i)$ Which solution has the highest concentration of $H^{+}$ ions?
$(ii)$ Which solution has the lowest concentration of $H^{+}$ ions?

At which value of $pH$ of the inner side of the mouth does the decay of teeth take place?

State what happens when zinc granules are heated with sodium hydroxide solution. Write the balanced equation for this reaction. Name the main product formed in this reaction.