In the synthesis of which compound is water gas used?

Which pair does not show hydrogen isotopes?

Assertion : Hydrogen combines with other elements by losing,gaining or sharing of electrons.
Reason : Hydrogen forms electrovalent and covalent bonds with other elements.

Which of the following will not be reduced by $H_2$?

Complete the following reactions:
$(i)$ $H_{2(g)} + M_mO_{o(s)} \xrightarrow{\Delta} M_{(s)} + H_2O_{(l)}$
$(ii)$ $CO_{(g)} + 2H_{2(g)} \xrightarrow{\Delta, \text{ catalyst}} CH_3OH_{(l)}$
$(iii)$ $C_3H_{8(g)} + 3H_2O_{(g)} \xrightarrow{\Delta, \text{ catalyst}} 3CO_{(g)} + 7H_{2(g)}$
$(iv)$ $Zn_{(s)} + 2NaOH_{(aq)} \xrightarrow{\text{heat}} Na_2ZnO_{2(aq)} + H_{2(g)}$

Which of the following statements concerning protium,deuterium and tritium is not true?