What do you mean by skeletal equation? 

What happens when current is passed through water? 

Define a reducing agent. 

In the reaction:

$2\mathrm{Pb}{\left({\mathrm{NO}}_3\right)}_2\left(\mathrm{s}\right)\stackrel{∆}{\to }2\mathrm{PbO}\left(\downarrow \right)+4{\mathrm{NO}}_2\left(\mathrm{g}\right)+{\mathrm{O}}_2\left(\mathrm{g}\right)$

What do the symbols $∆$ and $\downarrow$ signify?

Name the chemical reaction in which heat is absorbed.