Hydrogen has three isotopes $(A)$,$(B)$ and $(C)$. If the number of neutron$(s)$ in $(A)$,$(B)$ and $(C)$ respectively,are $(x)$,$(y)$ and $(z)$,the sum of $(x)$,$(y)$ and $(z)$ is:

Which of the following statements is not true?

The charring of sugar takes place when treated with concentrated $H_2SO_4$. What is the type of reaction involved in it?

The synonym for water gas when used in the production of methanol is:

Identify the correct statements from the following.
$(i)$ $Zn$ reacts with dilute $HCl$ and aqueous $NaOH$ solution separately and liberates hydrogen.
$(ii)$ $Ti$ and $Zr$ form interstitial hydrides.
$(iii)$ The viscosity of $H_2 O$ is more than the viscosity of $D_2 O$.

Which property of interstitial hydrides is correct?