NCERT Solutions for Chapter: Electrochemistry, Exercise 4: Intext Questions

If a current of $0.5$ ampere flows through a metallic wire for $2$ hours, then how many electrons would flow through the wire? 

Suggest a list of metals that are extracted electrolytically. 

Consider the reaction: $\mathrm{C}{\mathrm{r}}_2{\mathrm{O}}_7^{2-}+14{\mathrm{H}}^{+}+6{\mathrm{e}}^{-}\to 2\mathrm{C}{\mathrm{r}}^{3+}+7{\mathrm{H}}_2\mathrm{O}$

What is the quantity of electricity in coulombs needed to reduce $1 \mathrm{mol}$ of ${\mathrm{Cr}}_2{\mathrm{O}}_7^{2-}$?