In the production of hydrogen by the Bosch process,which of the following is used as a catalyst?

Identify the reactions in which $H_2$ is liberated? $(i)$ $Zn + NaOH_{(aq)} \longrightarrow$ $(ii)$ $HCOOH \xrightarrow[\text{Conc. } H_2SO_4]{373 \ K}$ $(iii)$ $CH_{4(g)} + H_2O_{(g)} \xrightarrow[Ni]{1270 \ K}$ $(iv)$ $Zn + H^+_{(aq)} \longrightarrow$ $(v)$ $C_{(s)} + H_2O_{(g)} \xrightarrow{1270 \ K}$

Which of the following pairs of reactions give $H_2$ gas as a product upon hydrolysis?

Liquid ammonia is used for refrigeration because

Consider the following statements about the hydrides: $(I)$ Sodium hydride with water liberates oxygen gas $(II)$ Methane,silane are examples of electron precise hydrides $(III)$ Ammonia and water molecules are examples of electron deficient hydrides $(IV)$ Hydrides of beryllium and magnesium are polymeric in structure. The correct statements are:

Which of the following is expected to be higher for a proton $(H^+)$ compared to other ions?