When sugar is brought into contact with concentrated $H_2SO_4$,it turns black due to .......

Arrange the following:
$(i)$ $CaH_{2}$,$BeH_{2}$,and $TiH_{2}$ in order of increasing electrical conductance.
$(ii)$ $LiH$,$NaH$,and $CsH$ in order of increasing ionic character.
$(iii)$ $H-H$,$D-D$,and $F-F$ in order of increasing bond dissociation enthalpy.
$(iv)$ $NaH$,$MgH_{2}$,and $H_{2}O$ in order of increasing reducing property.

Which of the following is used for the extraction of glue from bones?

Which compound on electrolysis produces $H_2$ gas at both electrodes?

Which of the following is distilled first during the fractional distillation of liquid air or mixtures of these gases?

Which of the following isotopes of hydrogen has the maximum sum of $e^- + p^+ + n^0$?