Identify the product formed by the action of $$\mathrm{H}_2(\mathrm{~g})$$ with $$\mathrm{CO}(\mathrm{g})$$ in presence of $$\mathrm{Ni}$$ ?

Calculate $$E^{\circ}$$ cell for following.

$$\mathrm{Zn}(s)\left|\mathrm{Zn}^{++}(1 \mathrm{M}) \| \mathrm{Pb}^{++}(1 \mathrm{M})\right| \mathrm{Pb}(s)$$ if $$E_{\mathrm{Zn}}^{\circ}=-0.763 \mathrm{~V}$$ and $$E_{\mathrm{Pb}}^{\circ}=-0.126 \mathrm{~V}$$

Which from following elements exhibits usual tendency to undergo reduction?

According to reaction,

$$\mathrm{Mg}(s)+2 \mathrm{HCl}(a q) \longrightarrow \mathrm{MgCl}_2(a q)+\mathrm{H}_2(g) \uparrow .$$

Calculate the mass of $$\mathrm{Mg}$$ required to liberate $$4.48 \mathrm{~dm}^3 \mathrm{~H}_2$$ at STP?

(Molar mass of $$\mathrm{Mg}=24 \mathrm{~g} \mathrm{~mol}^{-1}$$)